Abstract T MP119: Forced Swim Test as an Index of Post-Stroke Depression in Rats
Background: Depression is common after stroke. The Porsolt Forced Swim Test (FST) is used to screen for depression and response to therapy in rodent models. The duration of immobility is considered to be an indication of learned helplessness. In this study we aimed to characterize post-stroke depression using the FST.
Methods: Male Lewis (N=6), Wistar (N=5), and Sprague Dawley (SD; N=11) rats were subjected to the FST (10 minutes) prior to 2 hours middle cerebral artery occlusion (MCAO) and then again at 28 days after MCAO. Sham-operated animals were used as controls. The latency to immobility and the duration of immobility were assessed along with the maximum velocity of movement. Blood was obtained at the time of sacrifice and assayed for interleukin (IL)-1α, IL-1β and IL-10. Statistics are non-parametric; data are displayed as median and interquartile range.
Results: Prior to stroke, the latency to immobility was similar in all strains, but the duration of immobility was greater in Lewis rats (201 [159, 294] secs; P=0.039) than in Wistar (148 [106, 184] secs) and SD rats (136 [112, 200] secs). The maximal velocity of movement in Lewis rats (47 [42, 55] cm/sec; P=0.007) was faster than Wistar (29 [25, 41] cm/sec) and SD (39 [34, 46] cm/sec) rats. In comparison to strain matched sham-operated animals, stroke was associated with an increase in the period of immobility (P=0.088), a decrease in latency to immobility (P=0.019) and an increase in the maximal velocity of movements (P=0.033) in Lewis rats. No significant differences in FST behavior were seen in Wistar or SD rats. Plasma concentrations of IL-1α (P=0.001) and IL-10 (P=0.011) were highest in Lewis rats at the time of sacrifice. The duration of immobility was most highly correlated with IL-1β (r=0.663, P=0.003) and IL-10 (r=0.575, P=0.013).
Summary: At baseline, Lewis rats exhibit more depressive behavior than Wistar and SD rats, and stroke appears to enhance these differences. The change in behavior on the FST is associated with an increase in markers of systemic inflammation. The FST could be used to study interventions for post-stroke depression.
Author Disclosures: A. Kunze: None. D. Zierath: None. T. Barclay: None. K.J. Becker: Research Grant; Significant; NINDS. Other; Significant; outcomes adjudication committee for Merck.
This research has received full or partial funding support from the American Heart Association, Western States - Alaska, Arizona, California, Hawaii, Idaho, Montana, Nevada, Oregon, Utah, Washington.
- © 2014 by American Heart Association, Inc.