Unilateral infarction of the visual cortex (VC) induced an increase in dendritic spine turnover in contralateral VC.

After brain stroke, appropriate functional recovery is most important for improvement of quality of life. Cortical hemisphere contralateral to the infarction site plays an important role in functional recovery process. However, the underlying processes occurring in contralateral hemisphere during recovery has not yet been elucidated. We have previously reported that the turnover of synaptic spine of somatosensory cortex (SSC) is increased at 1st week after stroke in contralateral SSC infarction. After this period, neuronal circuit is remodeled, and functional compensation is achieved by processing bilateral information to remaining SSC [18]. In the present study, to examine whether similar changes are observed in different brain regions, we have induced an infarction in the visual cortex (VC). We found that the spinal remodeling in contralateral VC was also increased at 1st week after VC stroke. However, the magnitude of changes was not as great as those seen in SSC infraction. These results indicate that the regional difference may exist in the ability to induce functional recovery after ischemic brain damage.