Constraint-Induced Movement Therapy Enhanced Neurogenesis and Behavioral Recovery after Stroke in Adult Rats

Abstract

Constraint-induced movement therapy (CIMT) has been extensively used for stroke rehabilitation. CIMT encourages use of the impaired limb along with restraint of the ipsilesional limb in daily life, and may promote behavioral recovery and induce structural changes in brain after stroke. The aim of this study was to investigate whether CIMT enhances neurogenesis in rat brain after stroke that was generated by middle cerebral artery occlusion. Adult rats were divided into sham group, ischemia group and ischemia treated with CIMT group. Rats of CIMT group were treated with a plaster cast to restrain the healthy forelimb for 14 days beginning 1 week after ischemia. The proliferation of neuronal cells labeled with bromodeoxyuridine (BrdU) and behavioral recovery were analyzed at day 29 after ischemia. We also measured the tissue level of stromal cell-derived factor 1 (SDF-1) by ELISA. SDF-1 might be involved in the regulation of neurogenesis following stroke. In the subventricular zone of the animals treated with CIMT, there was a significant increase in the number of BrdU-positive cells (135 +/- 18, P < 0.05), compared with ischemia group (87 +/- 12) or sham group (18 +/- 3.6). Likewise, in the dentate gyrus, animals treated with CIMT showed a significant increase in BrdU-positive cells (296 +/- 26, P < 0.05) compared with ischemia group (225 +/- 18) or sham group (162 +/- 11). CIMT treatment after stroke significantly improved behavioral performances and increased the SDF-1 protein levels in the cortex and dentate gyrus. In conclusion, CIMT treatment enhances neurogenesis and functional recovery after stroke.