Abstract TP101: Gene Expression Profile After Repetitive Transcranial Magnetic Stimulation
Introduction: Although repetitive transcranial magnetic stimulation (rTMS) has been getting attention as a new therapeutic tool in stroke rehabilitation, little is known about its molecular mechanisms.
Objectives: We have performed microarray mRNA and miRNA analysis as well as miRNA-mRNA integrated analysis to investigate of rTMS-induced molecular changes at a genome-wide scale.
Methods: Eight adult male Sprague-Dawley rats were subjected to a single session of unilateral rTMS with 1 Hz (n=4) or sham (n=4) protocol to explore the immediate effect after rTMS. Additional 8 rats were assigned to receive either 1-Hz (n=4) or sham (n=4) rTMS for 5 consecutive days to the left hemisphere using the same protocol. The Illumina HumanHT-12 v3 Expression BeadChip microarray was used for mRNA expression analysis. Agilent Rat microRNA Microarrays (mirBASE 15.0) (Agilent Technologies, Inc. Santa Clara, CA) was used for additional analysis of miRNA.
Results: Microarray analysis reveals differentially expressed genes in the rat cortex after real or sham rTMS. Overrepresented gene ontology categories include positive regulation of axon extension, axonogenesis, intracellular transport, and synaptic plasticity after repetitive sessions of rTMS. A single session of rTMS, however, induced changes primarily in immediate early genes. In addition, several miRNAs showed significant inverse relationship with mRNAs.
Conclusion: We explored potential mechanisms of rTMS in a small animal model of unilateral hemispheric rTMS and confirmed its differential molecular effects on the stimulated cortices. Future study will be required to validate the functional significance of selected genes and to refine therapeutic use of rTMS. Figure 1. Cluster analysis for 200 probes of high fold-change did not show clear distinction between groups immediately after rTMS (A). Repetitive stimulation for 5 consecutive days shows, however, obvious difference of gene expression between groups (B).
- © 2012 by American Heart Association, Inc.