(Stroke. 1998;29:2381-2395.)
© 1998 American Heart Association, Inc.
Original Contributions |
Enhanced Neocortical Neural Sprouting, Synaptogenesis, and Behavioral Recovery With D-Amphetamine Therapy After Neocortical Infarction in Rats
From the School of Biological Sciences, Division of Neuroscience, University of Manchester, Manchester, England (R.P.S.), and Departments of Neurology (T.A.K.) and Anatomy and Neurosciences and Marine Biomedical Institute (C.E.H.), University of Texas Medical Branch, Galveston.
Correspondence to Dr C.E. Hulsebosch, Department of Anatomy and Neurosciences, 301 University Blvd 1069, University of Texas Medical Branch, Galveston, TX 77555-1069. E-mail CEHulseb{at}utmb.edu
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Abstract |
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Background and Purpose—D-Amphetamine administration increases behavioral recovery after various cortical lesions including cortical ablations, contusions, and focal ischemia in animals and after stroke in humans. The purpose of the present study was to test the enhanced behavioral recovery and increased expression of proteins involved in neurite growth and synaptogenesis in D-amphetamine–treated rats compared with vehicle-treated controls after a focal neocortical infarct.
Methods—Unilateral neocortical ischemia was induced in male spontaneously hypertensive Wistar rats (n=8 per time point per group) by permanently occluding the distal middle cerebral artery and ipsilateral common carotid artery in 2 groups of rats: D-amphetamine treated (2 mg/kg IP injections) and vehicle treated (saline IP injections). To determine the spatial and temporal distribution of neurite growth and/or synaptogenesis, growth-associated protein (GAP-43), a protein expressed on axonal growth cones, and synaptophysin, a calcium-binding protein found on synaptic vesicles, were examined by immunohistochemical techniques, and both density and distribution of reaction product were measured. Since the resulting infarction included a portion of the forelimb neocortex, behavioral assessments of forelimb function using the foot-fault test of Hernandez and Schallert were performed on the same rats used for immunohistochemical studies during the period of drug action and 24 hours later. A Morris water maze and other indices of behavioral assays were also measured similarly. Recovery times were 3, 7, 14, 30, and 60 days postoperatively.
Results—Both GAP-43 and synaptophysin proteins demonstrated statistically significant increases in density and distribution of immunoreaction product as determined by optical density measurements in the neocortex of the infarcted group treated with D-amphetamines compared with vehicle-treated infarcted controls. The GAP-43 was elevated to statistically significant levels in forelimb, hindlimb, and parietal neocortical regions ipsilateral to the infarction only at days 3, 7, and 14. By contrast, the synaptophysin demonstrated no statistically significant changes in expression at 3 or 7 days but demonstrated statistically significant increases at 14, 30, and 60 days in the forelimb, hindlimb, and parietal neocortical regions ipsilateral to the infarction as well as increased distribution in the contralateral parietal neocortex. Behavioral assessment of forelimb function indicated that improved recovery of forelimb placement on the side contralateral to the infarction was statistically significant in the D-amphetamine–treated group compared with the vehicle-treated group (P<0.025). Spatial memory, as measured with the Morris water maze, worsened in the vehicle-treated group compared with the D-amphetamine–treated group at 60 days (P<0.025).
Conclusions—These data support the occurrence of neurite growth followed by synaptogenesis in the neocortex in a pattern that corresponds both spatially and temporally with behavioral recovery that is accelerated by D-amphetamine treatment. While the specific mechanisms responsible for D-amphetamine–promoted expression of proteins involved in neurite growth and synaptogenesis and of enhanced behavioral recovery are not known, it is suggested that protein upregulation occurs as a result of functional activation of pathways able to remodel in response to active behavioral performance.
Key Words: amphetamines • cerebral ischemia • immunohistochemistry • neuronal plasticity • proteins • synaptophysin • rats
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Introduction |
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After focal neocortical ischemia, massive primary and secondary neuronal death will result in regions of denervation that provide a stimulus for undamaged neurons to sprout and establish new synaptic connections. We previously reported an upregulation of proteins involved in sprouting and synaptogenesis in ipsilateral and contralateral forelimb and parietal neocortices after cerebral infarction that correlated temporally with forelimb behavioral recovery.1 2 3 Although central nervous system (CNS) plasticity after trauma is a subject of controversy, the understanding of this and other mechanisms that provide a substrate for the recovery of function after neural trauma is important to effect improved patient outcome. For example, long-term treatment of patients with cerebral ischemia traditionally consists of symptom management and physical therapy.4 5 6 7 8
A promising approach in recovery from behavioral dysfunction after brain injury is the administration of pharmacological agents that increase release at noradrenergic terminals. One such promising compound, D-amphetamine sulfate (D-AMP), is postulated to involve interactions with noradrenergic transmitter systems in the brain, specifically the catecholamines: norepinephrine, dopamine, and serotonin. D-AMP administration 24 hours after injury in rats, 10 days after injury in cats, and as late as 2 to 4 weeks in stroke patients results in improved function after cortical ablation, cortical contusion, and stroke.9 10 11 12 13 14 15 16 Although the mechanisms of D-AMP action remain unclear and some studies show no effect,14 behavioral results with D-AMP after cerebral trauma or stroke are promising. The purpose of this study was to measure dysfunction and recovery with the use of behavioral models that test spatial memory and sensorimotor function in D-AMP–treated compared with vehicle-treated rats with unilateral neocortical infarction and to correlate these data with the expression of genes involved in neurite growth and synaptogenesis. The hypothesis to be tested is that D-AMP treatment improves behavioral outcome after neocortical infarction and that one mechanism of D-AMP action involves the upregulation of proteins involved in neuronal remodeling, which is achieved by activation of alternate neural pathways by behavioral use.
Neurite growth, a component of anatomic plasticity, can be identified by the elevated expression of a growth-associated protein identified with a molecular weight of 43 kDa (GAP-43).17 GAP-43 is a membrane-bound protein found in the axonal growth cones of sprouting CNS neurites.17 18 19 20 21 22 23 24 25 Another protein useful in the identification of axonal sprouting and synaptogenesis is synaptophysin, a presynaptic vesicle protein (molecular weight 38 000) that is found in all nerve terminals. Levels of synaptophysin within the terminal are believed to remain constant, along with several other vesicle proteins, because of the recycling of vesicle material in the nerve terminal,26 27 28 and they have been used by a variety of laboratories to quantify numbers of terminals during neuroanatomical remodeling and neural development.29 30 31 32 33 34
It is the objective of this study to use quantitative immunohistochemical techniques to determine increased expression by density and distribution measurements of GAP-43, as an indicator of neurite sprouting, and of synaptophysin, as an indicator of synaptogenesis. The expression of these proteins is measured in the neocortex after distal middle cerebral artery occlusion (dMCAo) with the use of the unilateral tandem occlusion model, in which focal cerebral cortical ischemia is produced by permanent dMCAo in spontaneously hypertensive Wistar rats (SHR).35 36 The use of the SHR strain provides spatially consistent and large neocortical infarct volumes because of the lack of anatomic variation in the middle cerebral artery (MCA) and the limited collateral circulation from anterior and posterior cerebral arteries. This results in highly reproducible, well-circumscribed focal ischemic injuries with very little to no penumbral region and no ischemic damage to subcortical structures.35 36 37 Thus, interanimal variability is reduced. Reproducibility of this focal ischemia model provides an important baseline for assessing changes in gene expression and behavioral recovery after treatment.
Since an important outcome measure is recovery of function, it is
meaningful to correlate the expression of GAP-43 and synaptophysin with
functional outcome in D-AMP–treated compared with vehicle-treated
rats. The region of the neocortical ischemia produced in this
model includes a portion of the forelimb neocortex (Figure 1
). Consequently, forelimb dysfunction on
the side contralateral to the ischemia is predicted, and we
have previously reported this outcome.3 If the
temporal expression of the proteins involved in neuroanatomical
remodeling is increased in appropriate neocortical regions, ie, the
forelimb, and this increase corresponds with the improvement of
forelimb function in D-AMP–treated rats compared with vehicle-treated
rats, then these data would provide support that D-AMP enhances
neuroanatomical remodeling and provides a mechanism for recovery of
function in this model. In addition, since the neocortical denervation
is extensive, alterations of spatial behavior brought about by
secondary and tertiary neuronal death might occur with a time course of
several days to weeks. Consequently, another aim of this study is to
test spatial memory performance of the rats by monitoring the
Morris water maze behavior over time and to compare the temporal
behavioral data with the temporal pattern of protein expression in
D-AMP–treated rats compared with vehicle-treated controls.
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Materials and Methods |
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Surgical Methods
Nonfasted male SHR (weight, 260 to 300 g) were anesthetized with halothane (4% induction/1% maintenance), placed on a heating pad, and given an antibiotic (streptomycin, 0.10 mL, 150 mg/mL IP). SHR were used to ensure constant infarction volume and placement because of poor collateral circulation and consistent vascular anatomy.36 With the use of surgical methods previously described briefly,1 2 3 the right common carotid sheath was ligated with 4-0 suture, and the distal portion of the MCA was permanently ligated with a 10-0 suture knot tied immediately proximal to the frontal branch. Sham controls were prepared for surgery similarly except that the 10-0 suture was not tied into a knot but was left in place. The animals recovered within 2 hours after surgery was completed. If an animal survived 12 hours after surgery, there was no subsequent mortality. Antibiotics (vancomycin, 0.10 mL, 150 mg/mL per day IP) were given for 2 days after surgery. The animals were then housed 2 to a cage. Functional damage could not be detected by gross motor and sensory observations. Animals were allowed to recover for time points of 3, 7, and 14 days and 1 and 2 months with n=8 for each group (D-AMP and vehicle injections) for each time point. The same animals in which behavioral tests were performed were killed at these time points for immunocytochemical reaction products, as described below. The original design of the experiment was to compare D-AMP– and vehicle-injected dMCAo animals against several control groups: (1) vehicle-injected sham-operated group; (2) vehicle-injected unoperated group; (3) D-AMP–injected sham-operated group; and (4) D-AMP–injected unoperated group. These control groups were designed to rule out confounding behavioral or immunocytochemical changes in response to D-AMP treatment. These control groups showed no statistical differences from naive animals in any test and are not discussed further. All procedures were approved by the University of Texas Medical Branch Animal Care and Use Committee.
D-Amphetamine Regimen
Animals were given a single intraperitoneal
injection of 2 mg/kg D-AMP dissolved in distilled water (10 mg/10 mL)
or vehicle on days 3, 6, and 13 and every third day until day 30. To
determine a reasonable test dose of D-AMP for the SHR strain before the
experimental design, 5 rats were tested behaviorally at 5 mg/kg, 5 at 3
mg/kg, and 5 at 2 mg/kg D-AMP in a single
intraperitoneal injection. Chronic injections of
D-AMP have been reported to result in excitotoxic neuronal death.
However, the experimental dose used (2 mg/kg) is <1/100 of the dose
reported in which excitotoxic neuronal death
occurs.38 In addition, we found no cell loss in
catecholaminergic neuronal populations, which are
reportedly more susceptible to excitotoxic effects of D-AMP injections,
in these animals. Animals were tested on the foot-fault test 1 hour
after injections test while the animals were intoxicated, a
"training" period according to the above injection regimen. All
behavioral tests were performed again, 24 hours after injection, for
both vehicle- and D-AMP–injected groups until the animals were killed
for immunocytochemistry. The foot-fault behavioral data
analyses include data for both the training and 24 hours after
intoxication. For the Morris water maze test, the same groups in the
foot-fault test were subjected to only 2 days of testing: the
behavioral intoxication training period, and behavioral tests 24 hours
after the injection (D-AMP or vehicle) on the day of euthanasia. Only
data collected on the day of euthanasia were analyzed. This
design eliminates any effect of multiple repeated maze testing over
time on the Morris water maze and effects that the amphetamine
intoxication may have had on swim speed and platform acquisition time.
One group each of D-AMP– and vehicle-injected animals was maintained
on the injection and training regimen for 30 days, then taken off both
the injection and testing regimens for 30 days and tested for
permanence of recovery (60-day group). The 3-day survival animals had
an injection on day 2 after dMCAo. All activity was recorded on
videotape for scoring at a later time. Because the treated groups were
killed for immunocytochemical analyses on the days described
below, the behavioral data between groups were analyzed with
the behavior recorded on the day of euthanasia. Thus, the
immunocytochemistry and behavioral data were collected from the same
group of animals at each time point.
Immunocytochemistry Methods
At various time points after surgery (3, 7, 14, 30, and 60
days), 2 groups of animals (n=8 in D-AMP–treated dMCAo groups and n=8
for vehicle-treated dMCAo groups) were anesthetized with sodium
pentobarbital and perfused transcardially with 4%
paraformaldehyde fixative in phosphate buffer
containing 0.1% picric acid. The brains were removed, photographed,
taken through graded sucrose solutions in fixative up to 30%, blocked
and embedded in OCT freezing compound (Miles, Inc), frozen, and stored
at -70°C. Cryosections (60 µm thick) were run as sets with
sections from infarcted brains and sham control brains run
simultaneously, as previously
described.3 Sections were
immunostained with a monoclonal antibody to either GAP-43
(Boehringer Mannheim) or synaptophysin (Boehringer
Mannheim) at a dilution of 1:500. Every fifth section was mounted on
gelatin-coated slides for silver staining. To ensure that
immunostaining was specific, control reactions were
immunostained in the same solutions with no primary
antibody, with glial fibrillary acidic protein primary antibody (1:500,
Boehringer Mannheim), or with a leukocyte common antigen
primary antibody (1:500, Chemicon). The tissue processed in the absence
of primary antibody had little immunostaining. The
glial fibrillary acidic protein antibody and the leukocyte common
antigen antibody caused immunostaining that was
specific for astrocytes or leukocytes, respectively, with relatively
homogeneous staining with the exception of a narrow band of
immunoreaction surrounding the infarction, which was subtracted from
the region analyzed for GAP-43 and synaptophysin. Optical
density measurements of immunoreacted tissue were made from an enlarged
image (x500) with a Quantex QX-7 Image Analyzer System
(Quantex Corp). With methods described
earlier,1 2 3 a standard square area was generated
(0.2x0.2 mm of tissue), and mean radiance (light transmission)
was measured on a scale of 0 to 256 relative units. This measurement
was repeated 5 times for each area, medial and lateral to the region of
damage. Limits of ischemic damage were delineated by
microscopic examination of adjacent sections with ammoniacal silver
staining. Density measurements were taken in a line perpendicular to a
tangent of the surface of the cortex. For comparison, similar
measurements were taken from analogous locations of the same anatomic
regions from sections with the same atlas coordinates in sham control
sections, processed for immunoreactivity at the same time as the
experimental sections. Background measures of immunoreactivity for each
section (5 measures per section) were determined by measuring in
regions of white matter (corpus callosum, anterior commissure, or
internal capsule) found on the section. These background measurements
were subtracted from the cortical measurements and normalized to
establish percent optical densities. Normalized optical densities of
the regions in the ischemic brains were then compared with
normalized optical densities from corresponding regions in sham control
sections. All tissue sections were coded, and data were collected by
laboratory personnel shielded from surgical status, time from injury,
and treatment status.
Areas of Increased Immunoreactivity
To examine increases in the distribution of enhanced
immunoreactivity, a threshold level was determined, and all readings
above this density were assigned a pseudocolor. The area measurement
was then calculated by computer calibration of an input scale relative
to pixel size with the "areal" function of the Quantex software.
This method was used to calculate the area and distribution of GAP-43
at 3 days after infarction and of synaptophysin at 60 days after
infarction in the cortical regions medial and lateral to the infarcted
region and in the contralateral cortex.
Quantification of Infarct Area and Volume
To establish the volume damage, photographs of whole brains were
taken through a surgical microscope. Prints (enlarged x8) were then
placed under a grid, and the area of the damage was measured (pallid
tissue due to poor perfusion of picric acid). The measurements were
repeated 3 times for each brain. Infarct volumes were then calculated
with the use of cortical depth from similar regions in sham control
sections.
Behavioral Methods
For locomotor assessment, the rats were placed on elevated
hexagonal grids of 2 sizes to test placement dysfunction of the forepaw
with the Hernandez-Schallert foot-fault test.39
The grids had openings of either 3 cm (small) or 6 cm (large). Both
grid sizes were chosen to allow comparison with other studies that use
either small or large grids. Rats place their paws on the wire while
moving along the grid. The rats were video recorded from below the
grid for ease in recording the stepping pattern. With each
weight-bearing step, the paw may fall or slip between the wires. This
is recorded as a foot fault. The number of faults for the forepaw
contralateral to the infarction is recorded along with the number
of successful steps and displayed as a percentage of contralateral
forelimb foot faults per forelimb steps. Faults were calculated for
both sizes of grids. Baseline percentages were acquired by testing
sham-operated rats and rats preoperatively (control). These faults are
usually symmetrical and occur <10% of the time (see Figure 7).
Animals that did not move were seldom a problem, but if this occurred
the animal was gently prodded on the rump to initiate weight-bearing
stepping. To reduce olfactory-cued behavior during grid testing, the
apparatuses were cleaned with a disinfectant (Quinticare)
between tests.
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To assess performance with the use of spatial memory, the Morris water maze test was used. A fiberglass tank, 6 feet in diameter and 3 feet deep, was filled with 12 cm of water. An 11-cm-tall platform made of clear acrylic plastic consisting essentially of polymethyl methacrylate with a circular surface 10 cm in diameter was placed into 1 of 4 positions in the pool. The platform was 1 cm below the surface of the water and thus was hidden from the view of an animal in the water. The test rat was placed in the pool facing the side of the tank and released at 1 of 4 starting positions, north, south, east, or west, which was determined at random. The swim time in the pool until acquisition and access to the platform was recorded. The test subjects were allowed to rest on the platform for 30 seconds and placed back in starting position, for a total of 4 tests from starting positions determined at random. The rat was then placed in a cage on top of a heating pad and allowed to rest for 15 minutes. After the rest period, the rat was placed back in the tank and was tested again for 2 more trials. Each day of testing consisted of 3 trials of 4 tests each. The animal's behavior was monitored and recorded on videotape for later analysis. The amount of time needed to find the platform was compared between blocks of testing at the level of the individual rat and between groups of rats.40 41 42 Although other motor performances on behavioral tests were measured, which included the following tests: (1) postural reflex test, (2) somatosensory disengage behavior, (3) rearing behavior, and (4) grip strength, there were no statistically significant differences between groups for any of these tests, and therefore there will be no further consideration of these results.
Initial analyses of main effect of amphetamine administration
on behavioral outcomes and normalized density readings of reaction
product were conducted with 1-way ANOVA. Post hoc multiple
Student's t tests were conducted for each specific time
point (3, 7, 14, 30, and 60 days) for comparison between groups with
adjusted 
-level (P<0.025) to correct for multiple
comparisons. To determine effects of amphetamine treatment on the area
of immunoreaction product or infarct volume, comparisons were made
between the D-AMP–treated and vehicle-treated dMCAo groups with
Student's t test with (P<0.05) set as the
confidence level. Correlations of immunohistochemical results and
behavioral results were analyzed for significance with paired
analysis (density measurements in the forelimb neocortical
region paired with contralateral foot-fault performance for
each animal) by Spearman rank order correlation, with a correlation
coefficient of >0.9 set as significant.
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Results |
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In the determination of the D-AMP dose response, it is of interest to note that preliminary injections of D-AMP in the amount of 5 mg/kg resulted in a death rate of 80% of the SHR. Lower doses of 3 mg/kg did not result in morbidity but produced extreme stereotypy, that is, the rats performed repetitive head movements and produced little locomotive behavior. We empirically determined that doses of 2 mg/kg IP produced an acceptable level of intoxication in this strain without evidence of D-AMP–induced neuronal toxicity,38 as determined by pathological assessments of paraffin sections stained with hematoxylin and eosin, thus confirming optimal single doses previously reported.12
Histology
At the time of euthanasia, the region supplied by the occluded
MCA, principally the parietal and occipital cortex, appeared infarcted,
as determined by gross inspection, because of a lack of color from the
picric acid in the perfusate and an inconsistent
texture compared with the surrounding cortex. The mean±SD value of
area of infarction in 12 brains of D-AMP–treated rats, chosen at
random, was 59.2±3.2 mm2, which can be
compared with the untreated mean area of 58.4±2.8
mm2 and was not statistically different. The mean
volume of the infarction in D-AMP–treated rats was calculated to be
88.8±9.6 mm3, which was not statistically
different compared with untreated value of 86.4±8.0
mm3. The region of ischemia was confined
to the neocortex (Figure 2). By
comparison, the contralateral neocortex regions appeared undamaged at 3
days both by gross inspection and in histological
sections. The histology of the hippocampus and other subcortical
structures appeared normal in hematoxylin and eosin–stained sections,
in thionin-stained sections, and in ammoniacal silver–stained
sections. Area cell counts of hematoxylin and eosin–stained sections
of the hippocampal CA1 region ipsilateral and contralateral to the
infarcted side demonstrated no difference in pyramidal cell
number between sham controls and D-AMP– or vehicle-treated infarcted
animals or between sides in the infarcted animals. Both of the lateral
ventricles and the third ventricle appeared enlarged in both the
D-AMP– and vehicle-treated dMCAo groups relative to noninfarcted
animals, as reported earlier.1 2 3 Sham-operated
animals did not have any damage when examined grossly or
histologically as determined by the ammoniacal silver
stains or by hematoxylin and eosin stains. For the immunoreaction
product, intensity of reaction product varied with each
reaction and from animal to animal but was consistent within
each animal and within each section. In all comparisons, there was no
statistical difference between preoperative and sham control
values.
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GAP-43 Immunoreactivity
The GAP-43 immunoreactivity in brain slices from vehicle-treated
animals was consistent with results from previous studies of
GAP-43 at 1 week after occlusion with no injection
schedule.2 3 The immunostaining
was heavier in areas of the cortex surrounding the infarction compared
with control levels of gray matter and with the cortex in the
contralateral hemisphere (Figure 3).
Immunostaining was also heavy in the hypothalamus and
in the cingulate gyrus in some animals (Figure 3). The D-AMP–treated
animals demonstrated a greater amount of GAP-43 immunoreactivity in the
neocortex both medial and lateral to the infarction compared with
contralateral cortex or compared with the same regions in
vehicle-treated animals at 3 and 7 days after infarction
(P<0.025; Figure 4). The
vehicle-treated animals had significantly higher levels of GAP-43
immunoreactivity in the neocortex surrounding the infarction at 3, 7,
and 14 days after occlusion (P<0.025). At the 30- and
60-day time points, there was no statistical difference within groups
or between groups. With the sham control values and background levels
within each animal normalized to 1 to allow between-animal group
comparisons, there was a significantly higher increase in GAP-43
immunoreactivity in the D-AMP–treated animals compared with
vehicle-treated animals, with a combined normalized optical density of
3.8±0.46 medial and 3.8±0.35 lateral to the infarct region compared
with 2.5±0.68 and 2.6±0.37, respectively, at 3 days after
infarction and 2.8±0.50 medial and 2.9±0.31 lateral to the infarct
region in the D-AMP–treated animals compared with 1.7±0.1 and
1.7±0.35, respectively, at 7 days after infarction (Figure 4). These
values are statistically significant between the D-AMP– and
vehicle-treated groups (P<0.025). The neocortical regions
with elevated density in both vehicle- and D-AMP–treated groups
correspond to the forelimb, the hindlimb, parietal regions 1 and 2, and
the temporal neocortical regions ipsilaterally. GAP-43
immunostaining was also elevated at these time points
in the cingulate and entorhinal cortices of both hemispheres and in the
thalamus in D-AMP– and vehicle-treated animals. Elevated staining was
also present in the hippocampus, dentate gyrus, and
septal/hypothalamic regions in sections of D-AMP–treated and
vehicle-treated animals and sham controls at all time points after
occlusion.
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The mean±SD values of the area measurements for the vehicle-treated group in the peri-infarct regions of increased GAP-43 density at the 3-day time point in sections at bregma -0.30 and interaural 8.70 were 1.01±0.45 mm2 medial to the infarct in the hindlimb neocortical region and 2.6±0.57 mm2 lateral to the infarct in the parietal 2 neocortical region. The area measurements of GAP-43 density in sections at bregma 0.70 and interaural 9.70 were 0.82±0.062 mm2 in the forelimb neocortical region and 1.28±0.35 mm2 lateral to the infarction in the parietal 1 neocortical region. For comparison, the area measurements of increased GAP-43 density in the D-AMP–treated group at 3 days were 1.34±0.45 and 2.85±0.52 mm2 medial and lateral to the infarction at bregma -0.30 and interaural 8.70, which was not significantly different than the vehicle group. Conversely, at bregma 0.70 and interaural 9.70, the area measurements were 2.54±0.25 and 1.73±0.22 mm2 for medial and lateral, respectively, and these 2 areas were increased and significantly different (P<0.05) compared with area measurements of similar regions in the vehicle-treated group.
Synaptophysin Immunoreactivity
The synaptophysin immunoreactivity in brain slices was also
consistent with results from previous studies showing increased
synaptophysin immunoreactivity in the cortex surrounding the area of
infarction and in the contralateral parietal cortex at 1
month.1 2 3 (Figure 5). The immunostaining
was diffuse in both hemispheres, with little staining in the corpus
callosum and other areas of white matter in both groups of animals.
There was no significant difference in staining in D-AMP– or
vehicle-treated rats at 3 and 7 days after infarction compared with
sham controls. By contrast, there were significant differences in
density compared with sham controls in the peri-infarct region and the
contralateral cortex, which corresponds to the parietal 1 cortex, at 14
days, 1 month, and 2 months in both D-AMP–treated and vehicle-treated
animals (P<0.025). Although the intensity of reaction
product varied from animal to animal, all animals in both the
vehicle- and D-AMP–treated dMCAo groups demonstrated increased
synaptophysin reaction product in the contralateral parietal 1
cortex as measured by image analyses. The ipsilateral
neocortical regions with elevated density in both vehicle- and
D-AMP–treated groups correspond to the forelimb, the hindlimb,
parietal regions 1 and 2, and the temporal neocortical regions
ipsilaterally. Synaptophysin immunoreactivity was also elevated at
these time points in the cingulate and entorhinal cortices of both
hemispheres and in the thalamus and septal/hypothalamic regions in both
D-AMP– and vehicle-treated animals compared with sham controls
(P<0.025). There was no statistical difference in the level
of synaptophysin immunoreactivity when we compared similar regions
between the D-AMP– and vehicle-treated rats at any time point (Figure 6).
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The mean±SD values of the area measurements of increased synaptophysin density in the vehicle-treated dMCAo group at the 60-day time point in sections at bregma -0.30 and interaural 8.70 were 1.03±0.21 mm2 medial to the infarct in the hindlimb neocortical region, 1.64±0.42 mm2 lateral to the infarct in the parietal 2 neocortical region, and 1.58±0.39 mm2 in the contralateral parietal 1 and 2 neocortical regions. The area measurements of synaptophysin density in this same group of animals in sections at bregma 0.70 and interaural 9.70 were 0.96±0.27 mm2 in the forelimb neocortical region, 1.71±0.25 mm2 lateral to the infarction in the parietal and insular neocortical regions, and 1.39±0.11 mm2 in the contralateral parietal 1 neocortical regions. For comparison, the area measurements of increased synaptophysin density in the D-AMP–treated dMCAo group at 60 days were 0.83±0.26, 1.19±0.29, and 1.88±0.08 mm2 medial, lateral, and contralateral to the infarction at bregma -0.30 and interaural 8.70, while at bregma 0.70 and interaural 9.70 the area measurements were 0.92±0.16, 1.61±0.77, and 2.16±0.34 mm2 for medial, lateral, and contralateral to the infarction, respectively. In both sections, the contralateral parietal 1 neocortex of the D-AMP–treated group demonstrated an increased distribution that was significantly different (P<0.05) compared with area measurements of similar regions in the vehicle-treated group.
Behavioral Tests
Hernandez-Schallert Foot-Fault Test
D-AMP–treated dMCAo rats had a significantly better
performance on the smaller grid than the vehicle-treated dMCAo
animals at 2 and 3 days after surgery. This continued throughout the
recovery period (P<0.025). Rats were tested for
performance 1 hour after injection, which was a training
period, and 24 hours later the test was repeated and recorded
(Figure 7
). The data displayed in Figures 7 and 8 are not data from the same groups
over time but represent the results from different groups'
performances either during a training period (at 2, 6, and 13
days and 1 month) or on the day of euthanasia (at 3, 7, and 14 days and
1 and 2 months) for immunocytochemical analysis. The
D-AMP–treated dMCAo group had no significant difference in the
performance from sham-operated animals at 6 days after
infarction on the small grid. This recovery persisted throughout the
time course of the experiment. Vehicle-injected dMCAo groups performed
significantly worse on the small grid at all test times compared with
sham controls. On large-grid performance, a similar pattern of
significant results was obtained.
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Morris Water Maze
Performance on the Morris water maze, displayed as
acquisition time from start to platform, is shown graphed in Figure 8.
At 3 days after infarction, the D-AMP–treated group did significantly
worse than the vehicle-injected dMCAo group (P<0.025),
suggesting that the D-AMP treatment 24 hours earlier during the
training session on day 2 affected platform acquisition in the testing
sessions. Spatial memory appeared not to be a factor in these trials
because the D-AMP–treated rats frequently bumped into the platform;
however, the rats did not ascend onto the platform. The acquisition
times of both the D-AMP– and the vehicle-treated groups were not
statistically different from each other or from sham-operated animals
at 7 and 14 days. However, the acquisition time of the vehicle-treated
group did increase significantly with increasing time after surgery,
being statistically significant at 1 and 2 months compared with the
D-AMP–treated animals but statistically significant from sham controls
only at 2 months (P<0.025). Swim speeds were measured for
all groups, since swim speed could significantly affect behavioral
assessments. No statistically significant difference was found between
control, vehicle-treated dMCAo, or D-AMP–treated dMCAo groups.
There were statistically significant correlations of contralateral forelimb behavioral performance on the Hernandez-Schallert foot-fault test and GAP-43 immunoreactivity in the forelimb neocortical region in D-AMP–treated groups that were significant for both grid sizes (correlation coefficient=0.9211, P=0.0167 for small grid; correlation coefficient=0.9177, P=0.0167 for large grid). There was a statistically significant negative correlation of improved foot-fault behavior and elevated synaptophysin immunoreactivity in the D-AMP–treated groups over time for the small-grid performance (correlation coefficient=-0.9747, P=0.0167) but not for large-grid performance (correlation coefficient=-0.8944, P=0.0833). Thus, the numbers of foot faults were at minimal values at the same time points that the synaptophysin optical densities were at maximal values.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferencesIntroduction Note Added in ProofReferences |
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To summarize the present study, we report that multiple intraperitoneal D-AMP treatments, accompanied by behavioral training during the period of drug effect, enhance behavioral recovery of sensorimotor function of the contralateral forelimb after neocortical infarction. Posttreatment performance on the Morris water maze test was statistically significant between D-AMP–treated and vehicle-treated animals because of the temporal degradation of performance of the vehicle-treated group. There was no difference in infarct volume between D-AMP–treated and vehicle-treated animals. In addition, we report a statistically significant increase in density and distribution of GAP-43 immunoreactivity in the peri-infarct region, including the forelimb neocortical region, and a statistically significant increase in distribution of synaptophysin immunoreactivity in the contralateral parietal cortex of D-AMP–treated rats compared with vehicle-treated rats with neocortical infarction. These data support the occurrence of neurite growth followed by synaptogenesis in the neocortex in a pattern that corresponds both spatially and temporally with contralateral forelimb behavioral recovery that is accelerated by D-AMP treatment. The high correlations between both GAP-43 and synaptophysin measures compared with foot-fault scores support a causal relationship. While the specific mechanism responsible for D-AMP–promoted expression of proteins involved in neurite growth and synaptogenesis and of enhanced behavioral recovery is not known, it is suggested that upregulation of proteins associated with neuronal remodeling occurs because of functional activation of pathways able to remodel in response to active behavioral performance. These data, when considered in the context of other D-AMP studies,12 13 14 suggest the usefulness of multiple-dose regimens of D-AMP treatment during the rehabilitation of patients with cortical ischemia or trauma.43 44
Most postischemic patients show some signs of recovery over time4 5 6 that include both motor and cognitive behavior.4 45 Studies in rats show that behavioral recovery may have both short- and long-term components, resulting from both the resolution of acute symptoms such as edema and diaschisis46 and longer-lasting changes from plasticity in the brain.47 48 49 50 51 Although the mechanisms of recovery are controversial, data exist that support long-term recovery in humans as a function of neuronal remodeling in the brain,45 52 53 54 particularly in the peri-infarct region and in regions homologous to the infarcted region in the contralateral cortex.1 2 3 50 51 55 56 57 58 Behavioral research in our laboratories and others shows recovery in rats after cortical ischemia and indicates that there may be a link between cortical neuronal remodeling and recovery.1 2 3 57 59 In this study we demonstrate improved behavioral recovery after neocortical ischemia with D-AMP treatment that is associated with the enhanced expression of molecules involved in neuronal remodeling.
Although the existence of neuronal remodeling, including sprouting and synaptogenesis, in the CNS after injury is controversial,45 52 60 61 several lines of evidence using behavioral and lesion paradigms in both humans and animal models are consistent with the existence of neuronal remodeling in the neocortex.52 62 63 64 65 66 67 68 For example, cortical lesions in rats result in increased dendritic branching69 70 or changes of electrophysiological functional maps, which are often accompanied by behavioral recovery.66 71 72 73 74 75 76 We and others have published results that support the expression of genes involved in neuronal remodeling after ischemia.1 2 3 57 Consequently, data supporting the existence of cortical plasticity in response to ischemia with accompanying behavioral modifications are accumulating.
A variety of techniques allow the examination of proteins correlated with neuronal remodeling. The 2 proteins used in the present study, GAP-43 and synaptophysin, are associated with neurite growth and synapse formation, respectively. GAP-43 is a membrane-bound protein found in the growth cones of sprouting CNS axons.19 21 29 77 78 79 80 81 It is thought that GAP-43 acts with Gi proteins to regulate metabolic responses to signals.22 By blocking GAP-43 expression with antisense oligonucleotide probes, neurite outgrowth can be eliminated in cultured neurons24; conversely, the transfection of fibroblasts to express GAP-43 will result in neuritelike process formation.25 Antibodies to GAP-43 have been used in the CNS to examine neuronal sprouting and regeneration.82 Synaptophysin, a presynaptic vesicle protein (molecular weight 38 000), is found in all nerve terminals. Levels of synaptophysin within the terminal are believed to remain constant along with several other vesicle proteins, owing to the recycling of vesicle material in the nerve terminal.26 27 28 Methods developed by Masliah et al30 32 allow the estimation of increases or decreases in synaptic numbers with the use of synaptophysin immunostaining and are now used by others in the fields of neuronal remodeling and neural development.29 30 31 32 33 34 83
Of interest is the distribution of these proteins in the peri-infarct and contralateral neocortex.1 2 3 Since the increased immunoreactivity of GAP-43 and synaptophysin is interpreted to indicate axonal growth and synaptogenesis, respectively, these data are consistent with enhanced neurite sprouting in these regions, which include the ipsilateral forelimb neocortex and the parietal 1 neocortex both ipsilaterally and contralaterally. It is of interest to compare our results with those obtained after either unilateral occlusion of the proximal MCA or a thrombotic infarction of the vibrissal barrel-field cortex that resides in the parietal neocortices to emphasize the importance of the contralateral cortex. In the unilateral proximal occlusion MCA model, behavioral recovery was demonstrated in tests for functional improvements of the forelimb, hindlimb, beam balance, and spontaneous limb use. Treatment with basic fibroblast growth factor significantly improved behavioral recovery compared with vehicle-treated groups. GAP-43 immunoreactivity was demonstrated in both the ipsilateral peri-infarct region and the contralateral cortex in both groups but demonstrated a selective increase in the contralateral sensorimotor cortex.57 In the barrel-field cortex of animals with unilaterally thrombotic infarctions of the vibrissal barrel-field cortex, the ability to respond to vibrissal sensory information with a motor task was impaired but recovered over time by 60 days. Bilaterally infarcted animals demonstrated no recovery.55 These data support the involvement of the intact contralateral cortex in the recovery of function. Furthermore, 2-deoxyglucose studies by the same group indicated that 30 days after the unilateral cortical infarction, activation of the vibrissae contralateral to the infarct resulted in a spread of activation anterior and lateral to the infarcted zone and included areas within the ipsilateral somatosensory cortex.84 Our studies confirm the involvement of the neocortex anteriorly, medial and lateral to the infarct and contralateral to the infarct, in that proteins known to be involved in neuroanatomical remodeling are upregulated in these regions1 2 3 and in response to D-AMP treatment (present study). Thus, the present studies confirm our earlier studies that behavioral recovery in unilaterally infarcted animals is a consequence of functional plasticity with resultant neural circuit reorganization and extend these findings to propose that neuroanatomical reorganization is one mechanism by which the neural circuit reorganization is achieved.68
Furthermore, D-AMP treatment improves behavioral recovery not only in the sensorimotor task of the forelimb behavior but also in the spatial memory tasks. The behavioral results of the Morris water maze indicate an improved long-term benefit in terms of sustained functional recovery of the D-AMP–treated animals compared with the vehicle-treated animals since the vehicle animals exhibited a worsening of behavior. To our knowledge, we are the first to report a delayed worsening of behavior in the Morris water maze test after cortical neurotrauma. By contrast, poor performance after the acute 2-day dose of D-AMP may be related to its monoaminergic agonist role14 directly in the spatial memory task or indirectly as related to a reduction in behavioral "stress" in general and postsurgical stress and/or pain specifically. Therefore, treatment with D-AMP may result in animal behavior in which water swimming is no longer stressful, and thus the motivation to acquire and ascend the platform is absent. Monoaminergic agonists or transport inhibitors are well known to produce feelings of well-being in patients. On the other hand, the worsening of the vehicle-treated groups is not surprising since rats suffering from traumatic brain injury are known to exhibit long-lasting memory deficits85 and rats sustaining a neocortical lesion or ablation demonstrate loss of spatial function,50 presumably as a result of delayed retrograde and orthograde neuronal death as well as the altered circuitry created in response to the loss of significant neuronal populations in the injured cortex. The cortical deafferentation is then followed by sequential loss of projection neurons and/or circuitry in the thalamocortical pathway, followed by loss of appropriate circuitry in the hippocampal-thalamic pathways. We propose that the increased neural sprouting and synaptogenesis induced by D-AMP treatment may have contributed to the improved temporal course of behavior over time due to trophic support from increased neural input onto neurons that would have died otherwise, thus rescuing these vulnerable neuronal populations.
While evidence is mounting that D-AMP administration for 24 hours after
injury indicates improved function after cortical ablation, contusion,
or ischemia,9 10 12 13 the mechanisms of
action remain unclear. One possible mechanism includes the ability of
D-AMP to stimulate presynaptic release of the
catecholaminergic terminals, which may act by disinhibition
of inhibitory circuits, resulting in overall increased
facilitation. Thus, cortical ablation or contusion experiments in which
administration of norepinephrine improves function may
occur through facilitatory, inhibitory, or both mechanisms
because the effect of norepinephrine is dependent on the
type of receptor activated (inhibition is mediated by
ß-norepinephrine receptors, while excitation is
mediated by -norepinephrine
receptors).86 In support of a facilitatory
mechanism, intracerebroventricular
injections of norepinephrine but not dopamine are reported
to improve recovery.12 87 Furthermore, with this
reasoning, lesions of the locus coeruleus, which give rise to massive
norepinephrine projections throughout the neuraxis,
could result in facilitation of locomotor behavior after cortical
injury; however, some experiments indicate facilitation of locomotor
recovery,88 and 1 report indicates impairment of
motor recovery after locus coeruleus lesions as a result of
norepinephrine depletion by systemic administration of
N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine.89
However, the involvement of norepinephrine in recovery is
well documented by many laboratories in which improved recovery with
norepinephrine agonists is
demonstrated,12 while impairment of recovery with
norepinephrine 1-receptor
antagonists (haloperidol, prazosin) as well as
dopamine antagonists (haloperidol) and
serotonin antagonists
(p-chlorophenylalanine) is demonstrated after cortical
injury.90 91 92
Another mechanism of D-AMP recovery is that norepinephrine and other catecholamines are involved with postinjury widespread metabolic depression,93 and thus D-AMP treatment, which is known to block posttraumatic depression of cortical metabolism,94 may act through a general mechanism contributing to increased metabolism.58 60 87 95 Another mechanism involves the activation of alternate pathways that, although normally depressed, could substitute to restore lost behavioral function. Thus, administration of D-AMP would result in activation of alternative pathways by, for example, increasing the size of cortical receptive fields responding to specific peripheral stimuli.84 An attractive mechanism involves D-AMP in cellular mechanisms that are responsible for learning and memory since D-AMP is effective if the animals are trained in the sensorimotor test during the D-AMP action.9 96 The relationship between D-AMP and learning is based on the involvement of catecholamines in the induction of long-term potentiation, a putative cellular mechanism of learning and memory. D-AMP is reported to facilitate the development of long-term potentiation in a dose-dependent manner97 and enhances memory retrieval.98
We propose an additional, nonexclusive, and novel mechanism for the action of D-AMP that involves the upregulation of genes involved in neuronal remodeling. For example, it is known that D-AMP can cause the induction of the immediate early gene c-fos.99 100 101 102 103 104 This induction is postulated to enhance the expression of proteins, including neurotrophins, that may be involved with dendritic and axonal sprouting105 106 in those pathways actively sprouting in response to the denervation. While sprouting is held by many to be a process that involves weeks, carefully done studies at the ultrastructural level demonstrate that synaptogenesis occurs in CNS regions and is complete in 3 to 6 days in the spinal cord107 and by 10 days in the red nucleus108 and is 30% complete in the septal nucleus by 10 days.109 Although the time course of CNS synaptogenesis may vary after denervation, it is well understood that denervated postsynaptic sites survive the loss of presynaptic elements and induce synaptogenesis, and the new synapses may be either homotypic (from the original innervation source) or heterotypic (from another innervation source). In addition, hierarchies of preference exist in which homotypic synaptogenesis will outcompete heterotypic synaptogenesis.109 110 The degree of homotypic versus heterotypic synaptogenesis will have functional consequences on recovery. We propose that D-AMP treatment in concert with performance of behavioral tasks can selectively upregulate neurite growth in those neural circuits able to subserve the behavioral function tested, despite the loss of the original pathways. Thus, physical therapy during the effective window of D-AMP treatment may improve recovery in patients with cortical ischemia and trauma.14 43 111
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Acknowledgments |
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This study was supported by grants NS 07185, NS 11255, and RR 03979 and by Bristol Myers–Squibb. The authors would like to thank Drs William D. Willis, Myron D. Ginsberg, and the reviewers for their careful reading and constructive criticism of this manuscript.
Received February 13, 1998; revision received July 22, 1998; accepted July 28, 1998.
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References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferencesIntroduction Note Added in ProofReferences |
|---|
1. Stroemer RP, Kent TA, Hulsebosch CE. Increase in synaptophysin immunoreactivity following cortical infarction. Neurosci Lett. 1992;147:21–24.[Medline] [Order article via Infotrieve]
2. Stroemer RP, Kent TA, Hulsebosch CE. Acute increase in expression of growth associated protein GAP-43 following cortical ischemia in rat. Neurosci Lett. 1993;162:51–54.[Medline] [Order article via Infotrieve]
3.
Stroemer RP, Kent TA, Hulsebosch CE. Neocortical
neural sprouting, synaptogenesis and behavioral recovery following
neocortical infarction in rats. Stroke. 1995;26:2135–2144.
4. Bach-y-Rita P. Brain plasticity as a basis for recovery of function in humans. Neuropsychologia. 1990;28:547–554.[Medline] [Order article via Infotrieve]
5. Frackowiak RS, Weiller C, Chollet F. The functional anatomy of recovery from brain injury. Ciba Found Symp. 1991;163:235–249.[Medline] [Order article via Infotrieve]
6.
Twitchell TE. The restoration of motor function
following hemiplegia in man. Brain. 1951;74:443–480.
7. Choi DW. Cerebral hypoxia: some new approaches and unanswered questions. J Neurosci. 1990;10:2493–2501.[Medline] [Order article via Infotrieve]
8.
Skilbeck CE, Wade DT, Hewer RL, Wood VA. Recovery
after stroke. J Neurol Neurosurg Psychiatry. 1983;46:5–8.
9. Feeney DM, Hovda DA. Reinstatement of binocular depth perception by amphetamine and visual experience after visual cortex ablation. Brain Res. 1985;342:352–356.[Medline] [Order article via Infotrieve]
10. Feeney DM, Westerberg VS. Norepinephrine and brain damage: alpha noradrenergic pharmacology alters functional recovery after cortical trauma. Can J Psychol. 1990;44:233–252.[Medline] [Order article via Infotrieve]
11. Hovda DA, Sutton RL, Feeney DM. Amphetamine-induced recovery of visual cliff performance after bilateral visual cortex ablation in cats: measurements of depth perception thresholds. Behav Neurosci. 1989;103:574–584.[Medline] [Order article via Infotrieve]
12. Feeney DM, Sutton RL. Pharmacotherapy for recovery of function after brain injury. Crit Rev Clin Neurobiol. 1987;3:135–197.
13. McIntosh TK. Neurochemical sequelae of traumatic brain injury: therapeutic implications. Cerebrovasc Brain Metab Rev. 1994;6:109–162.[Medline] [Order article via Infotrieve]
14. Feeney DM, Weisend MP, Kline AE. Noradrenergic pharmacotherapy, intracerebral infusion and adrenal transplantation promote functional recovery after cortical damage. J Neural Transplant Plast. 1993;4:199–213.[Medline] [Order article via Infotrieve]
15. Schmanke TD, Avery RA, Barth TM. The effects of amphetamine on recovery of function after cortical damage in the rat depend on the behavioral requirements of the task. J Neurotrauma. 1996;13:293–307.[Medline] [Order article via Infotrieve]
16. Schmanke TD, Barth TM. Amphetamine and task-specific practice augment recovery of vibrissae-evoked forelimb placing after unilateral sensorimotor cortical injury in the rat. J Neurotrauma. 1997;14:459–468.[Medline] [Order article via Infotrieve]
17. Skene H. Axonal growth-associated proteins. Ann Rev Neurosci. 1989;12:127–156.[Medline] [Order article via Infotrieve]
18.
Meiri K, Pfenninger KH, Willard MB. Growth-associated
protein, GAP-43, a polypeptide, that is induced when neurons extend
axons, is a component of growth cones and corresponds to pp46, a major
polypeptide of a subcellular fraction enriched in growth cones.
Proc Natl Acad Sci U S A. 1986;83:3537–3541.
19. Benowitz LI, Apostolides PJ, Perrone-Bizzozzero N, Finkelstein SP, Zwiers H. Anatomical distribution of the growth-associated protein GAP-43/B-50 in the adult rat brain. J Neurosci. 1988;8:339–352.[Abstract]
20. Goslin K, Scheyer D, Skene J, Banker G. Development of neuronal polarity: GAP-43 distinguishes axonal from dendrite growth cones. Nature. 1988;336:672–673.[Medline] [Order article via Infotrieve]
21. Oestreicher AB, De Graan PNE, Gispen WH, Verhaagen J, Schrama LH. B-50, the growth associated protein-43: modulation of cell morphology and communication in the nervous system. Prog Neurobiol. 1997;53:627–686.[Medline] [Order article via Infotrieve]
22. Strittmatter SM, Valenzuela D, Kennedy TE, Neer EJ, Fishman MC. Go is a major growth cone protein subject to regulation by GAP-43. Nature. 1990;344:836–841.[Medline] [Order article via Infotrieve]
23. Strittmatter S, Valenzuela D, Vartanian D, Sudo Y, Zuber M, Fishman M. Growth cone transduction: Go and GAP-43. J Cell Sci. 1991;15(suppl):27–33.
24. Fidel SA, Davies CR, Neve KA, Neve RL. Effects of manipulation of GAP-43 expression on morphology of PC12 cells and cultured hippocampal neurons. Soc Neurosci Abstr. 1990;6:339. Abstract.
25.
Zuber MX, Goodman DW, Karns LR, Fishman MC. The
neuronal growth-associated protein GAP-43 induces filopodia in
non-neuronal cells. Science. 1989;244:1193–1195.
26. Wiedenmann B, Franke WW. Identification and localization of synaptophysin and integral membrane glycoprotein of Mr 38,000 characteristic of presynaptic vesicles. Cell. 1985;41:1017–1028.[Medline] [Order article via Infotrieve]
27. Walaas SI, Jahn R, Greengard P. Quantitation of nerve terminal populations: synaptic vesicle-associated proteins as markers for synaptic density in the rat neostriatum. Synapse. 1988;2:516–520.[Medline] [Order article via Infotrieve]
28. Sudhof TC, Janh R. Proteins of synaptic vesicles involved in exocytosis and membrane recycling. Neuron. 1991;6:665–677.[Medline] [Order article via Infotrieve]
29. Masliah E, Fagan AM, Terry RD, DeTeresa R, Mallory M, Gage FH. Reactive synaptogenesis assessed by synaptophysin immunoreactivity is associated with GAP-43 in the dentate gyrus of the adult rat. Exp Neurol. 1991;113:131–142.[Medline] [Order article via Infotrieve]
30. Masliah E, Terry RD, DeTeresa R, Hansen LA. Immunohistochemical quantification of the synapse-related protein synaptophysin in Alzheimer disease. Neurosci Lett. 1989;103:234–239.[Medline] [Order article via Infotrieve]
31. Brock TO, O'Callaghan JP. Quantitative changes in the synaptic vesicle proteins synapsin 1 and p38 and the astrocyte-specific protein glial fibrillary acidic protein are associated with chemical-induced injury to the rat central nervous system. J Neurosci. 1987;7:931–942.[Abstract]
32. Masliah E, Terry, RD, Alford M, DeTeresa R. Quantitative immunohistochemistry of synaptophysin in human neocortex: an alternative method to estimate density of presynaptic terminals in paraffin sections. J Histochem Cytochem. 1990;38:837–844.[Abstract]
33. Cabalka LM, Ritchie TC, Coulter JD. Immunolocalization and quantitation of a novel nerve terminal protein in spinal cord development. J Comp Neurol. 1990;295:83–91.[Medline] [Order article via Infotrieve]
34. Wright DJ, Ritchie TC, Coulter JD. Distribution and developmental expression of the nerve terminal protein NT75 in the rat cerebellum. J Comp Neurol. 1991;304:530–543.[Medline] [Order article via Infotrieve]
35.
Chen ST, Hsu CY, Hogan EL, Maricq H, Balentine JD. A
model of focal ischemic stroke in the rat: reproducible
extensive cortical infarction. Stroke. 1986;17:738–743.
36. Brint S, Jacewicz M, Kiessling M, Tanabe J, Pulsinelli W. Focal brain ischemia in the rat: methods for reproducible neocortical infarction using tandem occlusion of the distal middle cerebral and ipsilateral common carotid arteries. J Cereb Blood Flow Metab. 1988;8:474–485.[Medline] [Order article via Infotrieve]
37.
Bradley RH, Kent TA, Eisenberg HM, Quast MJ. Middle
cerebral artery occlusion in rats studied by magnetic resonance
imaging. Stroke. 1989;20:1032–1036.
38. Persico AM, Schindler CW, Zaczek R, Brannock MT, Uhl GR. Brain transcription factor gene expression, neurotransmitter levels, and novelty response behaviors: alterations during rat amphetamine withdrawal and following chronic injection stress. Synapse. 1995;19:212–227.[Medline] [Order article via Infotrieve]
39. Hernandez TD, Schallert T. Seizures and recovery from experimental brain damage. Exp Neurol. 1988;102:318–324.[Medline] [Order article via Infotrieve]
40. Morris, R. Spatial localisation does not depend on the presence of local cues. Learning Motivation. 1981;12:239–260.
41. Morris, R. Development of a water maze procedure for studying spatial learning in the rat. J Neurosci Meth. 1984;11:47–60.[Medline] [Order article via Infotrieve]
42. Whishaw IQ, Mittleman G. Visits to starts, routes and places by rats (Rattus norvegicus) in swimming pool navigation tasks. J Comp Psychol. 1986;100:422–431.[Medline] [Order article via Infotrieve]
43. Wallesch CW, Muller U, Herrmann M. Aphasia: role of pharmacotherapy in treatment. CNS Drugs. 1997;7:203–213.
44. Walker-Batson D, Unwin H, Curtis S, Allen E, Wood M, Smith P, Devous MD, Reynolds S, Greenlee RG. Use of amphetamine in the treatment of aphasia. Restorative Neurol Neurosci. 1992;4:47–50.
45. Kertesz A. What do we learn from recovery from aphasia? Adv Neurol. 1988;47:277–292.[Medline] [Order article via Infotrieve]
46.
Feeney DM, Baron JC. Diaschisis. Stroke.. 1987;17:817–830.
47.
Persson L, Hardemark HG, Bolander HG, Hillered L,
Olsson Y. Neurologic and neuropathologic outcome after middle cerebral
artery occlusion in rats. Stroke. 1989;20:641–645.
48. DeRyck M, vanReempts J, Duytchaever H, vanDeuren B, Clinke G. Neocortical localization of tactile/proprioceptive limb placing reactions in the rat. Brain Res. 1992;573:44–60.[Medline] [Order article via Infotrieve]
49. Thomas RK. Immediate and subsequent effects of brain damage in rats. J Comp Physiol Psychol. 1966;62:472–475.
50. Markgraf CG, Green EJ, Hurwitz BE, Morikawa E, Dietrich WD, McCabe PM, Ginsberg MD, Schneiderman N. Sensorimotor and cognitive consequences of middle cerebral artery occlusion in rats. Brain Res. 1992;575:238–246.[Medline] [Order article via Infotrieve]
51. Markgraf CG, Green EJ, Watson B, McCabe PM, Schneiderman N, Dietrich WD, Ginsberg MD. Recovery of sensorimotor function after distal middle cerebral artery photothrombotic occlusion in rats. Stroke. 1994;25:153–159.[Abstract]
52. Finger S, Stein DG, eds. Brain Damage and Recovery Research and Clinical Perspectives. Orlando, Fla: Academic Press, Ind; 1982.
53. Wall PD. Recruitment of ineffective synapses after injury. In: Waxman SG, ed. Advances in Neurology, Vol 47: Functional Recovery in Neurological Disease. New York, NY: Raven Press; 1988:387–400.
54. Waxman SG. Functional recovery in diseases of the nervous system. Adv Neurol. 1988;47:1–7.[Medline] [Order article via Infotrieve]
55. Hurwitz BE, Dietrich WD, McCabe PM, Watson BD, Ginsberg MD, Schneiderman N. Sensory-motor deficit and recovery from thrombotic infarction of the vibrissal barrel-field cortex. Brain Res. 1990;512:210–220.[Medline] [Order article via Infotrieve]
56. Weiller C, Ramsay SC, Wise RJ, Friston KJ, Frackowiak RS. Individual patterns of functional reorganization in the human cerebral cortex after capsular infarction. Ann Neurol. 1993;33:181–189.[Medline] [Order article via Infotrieve]
57.
Kawamata T, Dietrich WD, Schallert T, Gotts JE, Cocke
RR, Benoqitz LI, Finklestein SP. Intracisternal basic fibroblast growth
factor enhances functional recovery and up-regulates the expression of
a molecular marker of neuronal sprouting following focal cerebral
infarction. Proc Natl Acad Sci U S A. 1997;94:8179–8184.
58. Dietrich WD, Watson BD, Busto R, Ginsberg MD. Metabolic plasticity following cortical infarction: a 2-deoxyglucose study in adult rats. In: Raichle ME, Powers WJ, eds. Cerebrovascular Diseases. New York, NY: Raven Press; 1987:285–295.
59. Greenough WT, Chang F-LF. Plasticity of synapse structure and pattern in the cerebral cortex. In: Peters A, Jones EG, eds. Cerebral Cortex: Development and Maturation of Cerebral Cortex. Vol 7. New York, NY: Plenum Press; 1988:391–440.
60. Boyeson MG, Feeney DM, Dail WG. Cortical microstimulation thresholds adjacent to sensorimotor cortex injury. J Neurotrauma. 1991;8:205–217.[Medline] [Order article via Infotrieve]
61. Brown PB. A reassessment of evidence for primary afferent sprouting in the dorsal horn. In: Pubols LM, Sessle BJ, eds. Effects of Injury on Trigeminal and Spinal Somatosensory Systems. New York, NY: Alan R. Liss; 1987.
62. Darian-Smith C, Gilbert CD. Axonal sprouting accompanies functional reorganization in adult cat striate cortex. Nature. 1994;368:737–740.[Medline] [Order article via Infotrieve]
63.
Singer W. Development and plasticity of cortical
processing architectures. Science. 1995;270:758–764.
64. Salin P, Tseng G-F, Hoffman S, Parada I, Prince DA. Axonal sprouting in layer V pyramidal neurons of chronically injured cerebral cortex. J Neurosci. 1995;15:8234–8245.[Abstract]
65. Buell SJ, Coleman PD. Quantitative evidence for selective dendritic growth in normal human aging but not in senile dementia. Brain Res. 1981;214:23–41.[Medline] [Order article via Infotrieve]
66. Chang FF, Greenough WT. Lateralized effects of monocular training on dendritic branching in adult split-brain rats. Brain Res. 1982;232:283–292.[Medline] [Order article via Infotrieve]
67. Juraska JM, Greenough WT, Elliott C, Mack KJ, Berkowitz R. Plasticity in adult rat visual cortex: an examination of several cell populations after differential rearing. Behav Neur Biol. 1980;29:157–167.[Medline] [Order article via Infotrieve]
68. Turner AM, Greenough WT. Differential rearing effects on rat visual cortex synapses, I: synaptic and neuronal density and synapses per neuron. Brain Res. 1985;329:195–203.[Medline] [Order article via Infotrieve]
69. Jones TA, Schallert T. Overgrowth and pruning of dendrites in adult rats recovering from neocortical damage. Brain Res. 1992;581:156–160.[Medline] [Order article via Infotrieve]
70. Jones TA, Schallert T. Use-dependent growth of pyramidal neurons after neocortical damage. J Neurosci. 1994;14:2140–2152.[Abstract]
71.
Allard T, Clark SA, Jenkins WM, Merzenich MM.
Reorganization of somatosensory area 3b representation in adult
owl monkeys after digital syndactyly. J Neurophysiol. 1991;66:1048–1058.
72. Jenkins WM, Merzenich MM, Recanzone G. Neocortical representational dynamics in adult primates: implication for neuropsychology. Neuropsychologia. 1990;28:573–584.[Medline] [Order article via Infotrieve]
73. Kolb B. Sparing and recovery of function. In: Kolb B, and Tees RC, eds. The Cerebral Cortex of the Rat. Cambridge, Mass: MIT Press; 1990:537–561.
74. Kolb B, Gibb R. Sparing of function after neonatal frontal lesions correlates with increased cortical dendritic branching: a possible mechanism for the Kennard effect. Behav Brain Res. 1991;43:51–56.[Medline] [Order article via Infotrieve]
75.
Nudo RJ, Milliken GW. Reorganization of movement
representations in primary motor cortex following focal
ischemic infarcts in adult squirrel monkeys. J
Neurophysiol. 1996;75:2144–2149.
76. Nudo RJ, Wise BM, SiFuentes F, Milliken GW. Neural substrates for the effects of rehabilitative training on motor recovery after ischemic infarct. Science. 1996;272:1791–1794.[Abstract]
77. Benowitz L, Rodriguez W, Neve R. The pattern of GAP-43 immunostaining changes in the rat hippocampal formation during reactive synaptogenesis. Mol Brain Res. 1990;8:17–23.[Medline] [Order article via Infotrieve]
78. Dunn-Meynell AA, Benowitz LI, Levin BE. Vibrissectomy induced changes in GAP-43 immunoreactivity in the adult rat barrel cortex. J Comp Neurol. 1992;8:160–170.
79.
Goslin K, Banker G. Rapid changes in the distribution
of GAP-43 correlate with the expression of neuronal polarity during
normal development and under experimental conditions. J Cell
Biol. 1990;110:1319–1331.
80. Levin BE, Dunn-Meynell A. Regulation of growth-associated protein 43 (GAP-43) messenger RNA associated with plastic change in the adult rat barrel receptor complex. Brain Res Mol Brain Res. 1993;18:59–70.[Medline] [Order article via Infotrieve]
81. Ng S, De la Monte SM, Conboy GL, Karns LR, Fishman MC. Cloning of human GAP-43: growth association and ischemic resurgence. Neuron. 1992;107:905–907.
82. Coggeshall RE, Reynolds ML, Woolf CJ. Distribution of the growth associated protein GAP-43 in the central processes of axotomized primary afferents in the adult rat spinal cord: presence of growth cone-like structures. Neurosci Lett. 1991;131:37–41.[Medline] [Order article via Infotrieve]
83. LeClerc N, Beesley PW, Brown I, Colonnier M, Gurd JW, Paladino T, Hawkes R. Synaptophysin expression during synaptogenesis in the rat cerebellar cortex. J Comp Neurol. 1989;280:197–212.[Medline] [Order article via Infotrieve]
84. Dietrich WD, Alonso O, Buston R, Watson BD, Loor Y, Ginsberg MD. Influence of amphetamine treatment on somatosensory function of the normal and infarcted rat brain. Stroke. 1990;21(suppl III):III-147–III-150.
85. Lyeth BG, Jenkins LW, Hamm RJ, Dixon CE, Phillips LL, Clifton GL, Young HF, Hayes RL. Prolonged memory impairment in the absence of hippocampal cell death following traumatic brain injury in the rat. Brain Res. 1990;526:249–258.[Medline] [Order article via Infotrieve]
86. Katzung BG, ed. Basic & Clinical Pharmacology. Stamford, Conn: Appleton & Lange; 1998.
87. Boyeson MG, Feeney DM. Intraventricular norepinephrine facilitates motor recovery following sensorimotor cortex injury. Pharmacol Biochem Behav. 1990;35:497–501.[Medline] [Order article via Infotrieve]
88. Weaver MS, Chen MJ, Westerberg VS, Feeney DM. Locus coeruleus lesions facilitate recovery of locomotor function after sensorimotor cortex contusion in rat. Neurosci Abstr. 1988;14:1451. Abstract.
89. Goldstein LB, Coviello A, Miller GD, Davis JN. Norepinephrine depletion impairs motor recovery following sensorimotor cortex injury in the rat. Restorative Neurol Neurosci. 1991;3:41–47.
90.
Feeney DM, Gonzalez A, Law WA. Amphetamine,
haloperidol, and experience interact to affect rate of recovery after
motor cortex injury. Science. 1982;217:855–857.
91.
Sutton RL, Feeney DM.
-Noradrenergic agonists and
antagonists affect recovery and maintenance of
bean-walking ability after sensorimotor cortex ablation in the rat.
Restorative Neurol Neurosci. 1992;4:1–11.
92. Pappius HM, Dadoun R, McHugh M. The effect of p-chlorophenylalanine on cerebral metabolism and biogenic amine content of traumatized brain. J Cereb Blood Flow Metab. 1988;8:324–334.[Medline] [Order article via Infotrieve]
93.
Ginsberg MD, Welsh FA, Budd WW. Deleterious effect of
glucose pretreatment on recovery from diffuse cerebral ischemia
in the cat, I: local cerebral blood flow and glucose utilization.
Stroke. 1980;11:347–354.
94. Brusino FG, Reves JG, Prough DS. The effect of age on cerebral blood flow autoregulation during hypothermic cardiopulmonary bypass. J Thorac Cardiovasc Surg. 1988;67:A10. Abstract.
95. Queen SA, Chen MJ, Feeney DM. D-Amphetamine attenuates decreased cerebral glucose utilization after unilateral sensorimotor cortex contusion in rats. Brain Res. 1997;777:42–50.[Medline] [Order article via Infotrieve]
96. Sutton RL, Hovda DA, Feeney DM. Amphetamine accelerates recovery of locomotor function following bilateral frontal cortex ablation in cats. Behav Neurosci. 1989;103:837–841.[Medline] [Order article via Infotrieve]
97. Gold PE, Delonay RL, Merrin J. Modulation of long-term potentiation by peripherally administered amphetamine and epinephrine. Brain Res. 1984;305:103–107.[Medline] [Order article via Infotrieve]
98. Altman HJ, Quartermain D. Facilitations of memory retrieval by centrally administered catecholamine stimulating agents. Behav Brain Res. 1983;7:51–63.[Medline] [Order article via Infotrieve]
99. An G, Lin T-N, Liu J-S, Xue J-J, He Y-Y, Hsu CY. Expression of c-fos and c-jun family genes after focal cerebral ischemia. Ann Neurol. 1993;33:457–464.[Medline] [Order article via Infotrieve]
100. Bjelke B, Bach-y-Rita P, Andersson C, Fuxe K. Changes in patterns of c-fos immunoreactive neurons in the rat tel- and di-encephalon following d-amphetamine treatment combined with motor training following unilateral lesion of the sensory-motor cortex. Soc Neurosci Abstr. 1992;18:371. Abstract.
101. Fuxe K, Agnati LF, Rosen L, Bjelke B, Cintra A, Bortolotti F, Tinner B, Steinbusch H, Gustagsson J-A, Benefati F. Computer-assisted image analysis techniques allow a characterization of the compartments within the basal ganglia: focus on functional compartments produced by d-amphetamine activation of the c-fos gene and its relationship to the glucocorticoid receptor. J Chem Neuroanat. 1991;4:355–372.[Medline] [Order article via Infotrieve]
102.
Graybiel AM, Moratalla R, Robertson HA. Amphetamine
and cocaine induce drug-specific activation of the c-fos gene in
striosome-matrix compartments and limbic subdivisions of the striatum.
Proc Natl Acad Sci U S A. 1990;87:6912–6916.
103.
Nguyen TV, Kosofsky BE, Birnbaum R, Cohen B, Hyman S.
Differential expression of c-fos and zif268 in rat striatum after
haloperidol, clozapine, and amphetamine. Proc Natl Acad Sci
U S A. 1992;89:4270–4274.
104. Naranjo JR, Mellstrom B, Achaval M, Lucas JJ, Del Rio J, Sassone-Corsi P. Co-induction of jun B and c-fos in a subset of neurons in the spinal cord. Oncogene. 1991;6:223–227.[Medline] [Order article via Infotrieve]
105.
Visvader J, Sasson-Corsi P, Verma IM. Two adjacent
promoter elements mediate nerve growth factor activation of the c-fos
gene and bind distinct nuclear complexes. Proc Natl Acad Sci
U S A. 1988;85:9474–9478.
106.
Wu B, Fodor EJB, Edwards RH, Rutter WJ. Nerve
growth factor induces the proto-oncogene c-jun in PC12 cells.
J Biol Chem. 1989;264:9000–9003.
107. Murray M, Goldberger ME. Replacement of synaptic terminals in lamina II and Clarke's nucleus after unilateral lumbosacral dorsal rhizotomy in adult cats. J Neurosci. 1986;6:3205–3217.[Abstract]
108. Tsukahara N. Synaptic plasticity in the red nucleus and its possible behavioral correlates. In: Cotman CW, ed. Synaptic Plasticity. New York, NY: Guilford Press; 1985:201–229.
109. Raisman G. Synapse formation in the septal nuclei of adult rats. In: Cotman CW, ed. Synaptic Plasticity. New York, NY: Guilford Press; 1985:13–38.
110. Goldberger ME. Spared root deafferentation of a cat's hindlimb: hierarchical regulation of pathways mediating recovery of motor behavior. Exp Brain Res. 1988;73:329–342.[Medline] [Order article via Infotrieve]
111. Crisostomo EA, Duncan PW, Propst M, Dawson DV, Davis JN. Evidence that amphetamine with physical therapy promotes recovery of motor function in stroke patients. Ann Neurol. 1988;23:94–97.[Medline] [Order article via Infotrieve]
112. Zilles K. Anatomy of the neocortex: cytoarchitecture and myeloarchitecture. In: Kolb B, RC Tees RC, eds. The Cerebral Cortex of the Rat. Cambridge, Mass: MIT Press; 1990.
113. Paxinos G, Watson C, eds. The Rat Brain in Stereotaxic Coordinates. New York, NY: Academic Press Inc; 1982.
Editorial Comment
Departments of Psychology and Neurosciences University of New Mexico Albuquerque, NM
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Despite the widespread pessimistic attitude toward treatment of brain damage in 1970, Stroke was founded with the goal of developing treatments from the combined effort of basic scientists and clinicians focused on this intractable problem. In the past decade this attitude has reversed to one of optimism and an expanding research effort devoted to reducing stroke severity. However, this approach of lessening the primary injury is unlikely to help the majority of stroke patients. There is considerable evidence that the therapeutic window for limiting the extent of primary damage is between 3 and 6 hours.1 2 Since the signs and symptoms of stroke do not cause pain or external bleeding, most patients consider their symptoms minor and do not seek medical attention within 6 hours after the stroke.3 For the treatment of the majority of stroke patients first seen after the window for early intervention has closed, it is important to investigate potential therapies that can be initiated late after stroke. To my knowledge, there is only 1 established intervention that enhances both the rate of recovery and level of ultimate outcome after stroke and other types of brain injury: the single or short-term administration of any of the family of drugs enhancing levels of central norepinephrine combined with symptom-relevant experience or physical therapy (PT) during the period of drug action.4 This intervention, termed norepinephrine/PT, produces an increase in the rate of recovery and an enduring enhancement of the ultimate outcome level. This experimental therapy promotes recovery from hemiplegia in brain-injured hemiplegic rats when treatment is delayed until 24 hours after injury and in cats when delayed for 10 days. These data have been recently reviewed.5 6 7 8 9 10 One small, double-blind study of moderate or severely affected stroke patients reported significantly improved outcome from hemiplegia when treatment was initiated as late as 30 days after the infarct, and the ultimate level of recovery remained significantly higher for the treated group compared with placebo/PT controls 1 year after stroke or 8 months after cessation of treatment.11 In the accompanying article by Stroemer et al, this experimental treatment was begun 3 days after an infarct in a rodent stroke model, and short-term treatment successfully promoted recovery of sensorimotor and cognitive deficits.
A unique aspect of the theoretical approach by Stroemer et al is
that the neurophysiological measurements were
focused on normal intact tissue adjacent or contralateral to the
primary injury, which was unaffected by the treatment regimen. Because
this treatment is effective when started days to weeks after injury and
also produces a very rapid improvement, previous hypotheses of the
mechanism of the norepinephrine/PT effect centered on
remote metabolic dysfunction in areas connected to the
primary injury. Supporting this hypothesis are studies reporting that
delayed D-AMP administration produces an enduring normalization of
postinjury hypometabolism that is worsened by
1-noradrenergic
antagonists.6 7 12 13 14 15 16 The
study by Stroemer et al evaluated a different hypothesis of
processes evoked by this treatment in remote intact tissue. Using
immunohistochemistry measures of the growth-associated proteins GAP-43
and synaptophysin, they report that norepinephrine/PT
treatment enhances both proteins at different times after injury. By
measuring temporal changes of both behavioral recovery and
growth-associated proteins, the authors found that D-AMP not only
enhances the amount of GAP-43 but that the amount of change was highly
correlated with sensorimotor recovery. These observations strengthen
the authors' proposal for a causal role for neural remodeling as a
mechanism whereby this treatment enhances functional recovery.
The authors' suggestion that multiple mechanisms may underlie this treatment effect is quite important. At the behavioral level of analysis, with measures of grid walking for assessment of sensorimotor symptoms and the Morris water maze for assessment of cognitive deficits, recovery of a deficit may appear as a single phenomenon. However, investigations of the mechanisms of this treatment reveal multiple correlated physiological processes. As the authors suggest, the rapid enhancement of recovery from hemiplegia after this intervention may result from alleviation of metabolic depression, but neuronal remodeling may contribute to the later stages of treatment-enhanced recovery.
A few issues must be investigated to clarify and confirm the
important observations and neuronal remodeling hypothesis of the
norepinephrine/PT treatment proposed by Stroemer et al.
First, their conclusion that neural sprouting and synaptogenesis are
enhanced by the treatment is only an inference from measures of the
amount of growth-associated proteins. It is a likely inference, but
direct measures of neuronal growth must be made to confirm their
interpretation. This is important because the authors note that GAP-43
and synaptophysin are associated with the release of transmitters,
including both noradrenaline and
dopamine.17 18 Enhanced release of these
neurotransmitters could be more important for functional recovery than
neuronal remodeling. Second, as noted by the authors, numerous studies
have demonstrated that the family of drugs increasing central
norepinephrine levels, when combined with PT, promotes
recovery. It is not known which catecholamine increases the
levels of these growth-associated proteins. Third, even if enduring
recovery is attributable to neuronal remodeling, such new wiring must
be regulated by
1-noradrenergic receptors. It
is important to recall that the relation between
norepinephrine and functional recovery has 2 aspects: drugs
increasing norepinephrine combined with PT enhance
recovery, whereas drugs reducing norepinephrine slow
recovery when given early after injury and transiently reinstate
deficits in recovered animals. The laboratory and clinical studies of
harmful effects on recovery of drugs reducing central
norepinephrine levels have been recently
reviewed.6 7 10 19 20 21 22 A short movie of the
reinstatement of hemiplegia by an
1-noradrenergic
antagonist months after recovery and a second movie
illustrating rapid recovery after D-AMP given 24 hours after brain
injury can be downloaded from my Web site:
http://www.unm.edu/~feeney/index.html. At least for hemiplegia, the
state we call recovery remains vulnerable to disruption long after
apparent remission of symptoms.22
Finally, some comment should be made regarding the increased death of animals given high doses of D-AMP in the pilot studies by Stroemer et al. This is apparently a strain-specific response to high doses. In another study evaluating this treatment in which Sprague-Dawley rats and homologous blood clots were used to produce a severe stroke with high mortality, a significant reduction of mortality was observed in the treatment group compared with saline controls.23 In addition, when higher doses of D-AMP in a photothrombotic rat stroke model were used, enhanced recovery and evidence for use of alternative circuits were reported, but no increase in mortality was noted.15 16 More importantly, no undue side effects have been reported in human studies in which >50 aphasic and/or hemiplegic stroke patients were treated with the norepinephrine/PT therapy (D. Walker-Batson, PhD, personal communication, 1998).
Regardless of these issues, the study by Stroemer et al not only adds to the growing literature on the efficacy of this late experimental therapy for stroke but provides a novel hypothesis regarding the mechanisms of the effect.
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferencesIntroduction Note Added in ProofReferences |
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A recent clinical study provides additional support for the norepinephrine/PT strategy for promoting recovery in stroke patients. The investigation describes enhanced functional motor recovery and less depression after stroke through short-term treatment with methylphenidate24 in conjunction with PT. This new study is an extension of laboratory studies of methylphenidate25 and supports the utility of the rat hemiplegia model for predicting drug effects on symptoms in stroke patients.
Received February 13, 1998; revision received July 22, 1998; accepted July 28, 1998.
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References |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferencesIntroduction Note Added in ProofReferences |
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1. Bath PMW. Treating acute ischaemic stroke. Br Med J.. 1995;311:139–140.
2. Ginsberg MD, Pulsinelli WA. The ischemic penumbra, injury thresholds, and the therapeutic window for acute stroke. Ann Neurol.. 1994;36:553–554.[Medline] [Order article via Infotrieve]
3.
Williams LS, Bruno A, Rouch D, Marriott DJ. Stroke
patients' knowledge of stroke: influence on time to
presentation. Stroke. 1997;28:912–915.
4. Feeney DM, Gonzalez A, Law WA. Amphetamine, haloperidol and experience interact to affect rate of recovery after motor cortex injury. Science. 1982;217:855–857.
5. Feeney DM. From laboratory to clinic: noradrenergic enhancement of physical therapy for stroke or trauma patients. In: Freund H-J, Sabel BA, Witte OW, eds. Brain Plasticity: Advances in Neurology. Philadelphia, Pa: Lippincott-Raven Publishers; 1997:383–394.
6. Feeney DM. Rehabilitation pharmacology: noradrenergic enhancement of physical therapy. In: Ginsberg MD, Bogousslavsky J, eds. Cerebrovascular Disease: Pathophysiology, Diagnosis and Management. Vol I. Cambridge, Mass: Blackwell Scientific Press; 1998:620–636.
7. Feeney DM. Mechanisms of noradrenergic modulation of physical therapy: effects on functional recovery after cortical injury. In: Goldstein LB, ed. Restorative Neurology: Advances in the Pharmacology of Recovery After Stroke. Armonc, NY: Futura Publishing Co, Inc; 1998:35–78.
8. Feeney DM. Pharmacologic modulation of recovery after brain injury: a reconsideration of diaschisis. J Neurol Rehabil.. 1991;5:113–128.
9. Feeney DM. Brain damage in a traumatic brain injury model: noradrenergic pharmacotherapy promotes functional recovery. In: Toole JF, Good DC, eds. Neuroimaging in Rehabilitation: Comprehensive Neurological Rehabilitation. Vol 9. Demos Vermande, NY: 1996:91–124.
10. Feeney DM, Weisend MP, Kline AE. Noradrenergic pharmacotherapy, intracerebral infusion and adrenal transplantation promote functional recovery after cortical damage. J Neurotrans Plast. 1994;4:199–214.
11.
Walker-Batson D, Smith P, Curtis S, Unwin H,
Greenlee RG. Amphetamine paired with physical therapy accelerates motor
recovery following stroke: further evidence. Stroke.. 1995;26:2254–2259.
12. Queen S, Chen M, Feeney DM. Amphetamine alleviates the reduced local cerebral glucose utilization produced by traumatic brain injury. Brain Res. 1997;777:42–50.
13. Feeney DM, Baron J-C. Diaschisis. Stroke. 1986;17:817–830.
14. Hovda DA, Sutton RL, Feeney DM. Recovery of tactile placing after visual cortex ablation in cat: a behavioral and metabolic study of diaschisis. Exp Neurol. 1987;97:1–12.[Medline] [Order article via Infotrieve]
15.
Hurwitz BE, Dietrich WD, McCabe PM, Alonso O,
Watson BD, Ginsberg MD, Scheiderman N. Amphetamine promotes recovery
from sensory-motor integration deficit after thrombotic infarction of
the primary somatosensory rat cortex. Stroke.. 1991;22:648–654.
16. Dietrich WD, Alonso O, Busto R, Ginsberg MD. The effect of amphetamine on functional brain activation in normal and post-infarcted rat. Stroke. 1990;21(suppl III):III-147–III-150.
17. Dekker LV, De Graan PN, Oestreicher AB, Versteeg DH, Gispen WH. Inhibition of noradrenaline release by antibodies to B-50 (GAP-43). Nature.. 1989;342:74–76.[Medline] [Order article via Infotrieve]
18.
Iwata SI, Hewlett GH, Ferrell ST, Kantor L, Gnegy ME.
Enhanced dopamine release and phosphorylation of
synaptophysin I and neuromodulin in striatal synaptosomes after
repeated amphetamine. J Pharmacol Exp Ther.. 1997;283:1445–1452.
19. Goldstein LB. Potential impact of drugs on poststroke motor recovery. In: Goldstein LB, ed. Restorative Neurology: Advances in the Pharmacology of Recovery After Stroke. Armonc, NY: Futura Publishing Co, Inc; 1998:241–256.
20. Feeney DM, Westerberg VS. Norepinephrine and brain damage: alpha noradrenergic pharmacology alters functional recovery after cortical trauma. Can J Psychiatry. 1990;44:233–252.
21.
Goldstein LB, Sygen in Acute Stroke Study
Investigators. Common drugs may influence motor recovery after stroke.
Neurology. 1995;45:865–871.
22. Stibick DL, Feeney DM. Alpha 1 noradrenergic antagonists reinstatement of hemiplegia in rats recovered after cerebral trauma does not lessen with time after injury. Neurosci Abst. In press.
23. Salo AA, Feeney DM. Reduction of morbidity, mortality and lesion size in rat model of cerebral infarction with amphetamine. Neurosci Abst. 1987;13:1268. Abstract.
24. Grade C, Redford B, Chrostowski J, Toussaint L, Blackwell B. Methylphenidate in early poststroke recovery: a double-blind, placebo-controlled study. Arch Phys Med Rehabil. 1998;79:1047–1050.[Medline] [Order article via Infotrieve]
25. Kline AE, Chen MJ, Tso-Oliveras DY, Feeney DM. Methylphenidate treatment following ablation induced hemiplegia: experience during drug action alters effects on recovery of function. Pharm Biochem Behav. 1994;48:773–779.[Medline] [Order article via Infotrieve]
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S. C. Cramer, C. I. Moore, S. P. Finklestein, and B. R. Rosen A Pilot Study of Somatotopic Mapping After Cortical Infarct Stroke, March 1, 2000; 31(3): 668 - 671. [Abstract] [Full Text] [PDF]
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B. B. Johansson Brain Plasticity and Stroke Rehabilitation : The Willis Lecture Stroke, January 1, 2000; 31(1): 223 - 230. [Abstract] [Full Text] [PDF]
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Recommendations for Standards Regarding Preclinical Neuroprotective and Restorative Drug Development Stroke, December 1, 1999; 30(12): 2752 - 2758. [Abstract] [Full Text] [PDF]
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L. B. Goldstein and C. E. Hulsebosch Amphetamine-Facilitated Poststroke Recovery • Response Stroke, March 1, 1999; 30(3): 696 - 698. [Full Text] [PDF]
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