Comparison of histological changes between symmetric and asymmetric groups. Neuronal damage was not seen in any mouse within the symmetric group. However, the asymmetric group showed evidence of neuronal necrosis and apoptosis using cresyl violet and caspase-3 staining, respectively. (A) Cresyl violet staining in the cortex of the mouse brain. (B) The number of neuronal cells that survived tended to decrease in the ischemic hemisphere of the asymmetric group compared to symmetric group; however, this was not statistically significant (p=0.186). (C) Immunohistochemistry of active caspase-3 in the cortex of the ischemic hemisphere. (D) Apoptotic cells were frequently observed in the ischemic hemisphere of the asymmetric group compared to the symmetric group; however, this was not statistically significant (p=0.177). Data are expressed as the mean±standard error of the mean (n=6/group).