The effect of a skilled reaching task on hippocampal plasticity after intracerebral hemorrhage in adult rats

[Purpose] The primary objective of this study was to assess the effects of a skilled reaching task on cognition, as indexed by the pattern of GAP-43 expression in the hippocampus, following intracerebral hemorrhage (ICH) in rats (when the hippocampus plays a critical role in spatial memory and learning). [Subjects and Methods] The model of ICH used in the present study involved intrastriatal injection of collagenase. Sixty male Sprague-Dawley rats (aged 12 weeks) were randomly assigned to either a control (n = 30; CON) or skilled reaching training group (n = 30; SRT). The SRT group were trained 5 days per week for 4 weeks following ICH. Animals were sacrificed 1, 2, or 4 weeks after ICH. Western blot analysis was used to evaluate GAP-43 expression. [Results] GAP-43 expression was increased in the SRT group, in accordance with greater elapsed time, but decreased in the CON group. At 1 week post injury, there were no significant differences between the CON and SRT groups. However, there were significant differences at both 2 and 4 weeks. [Conclusion] The present findings suggest that increased GAP-43 expression in the hippocampus following skilled reaching training may result in enhanced cognition and neural plasticity following ICH.