Cortical neuron apoptosis after mechanical subcortical transection in rats

    GAO Liª²Gui, WANG Huiª²Fang, LIU Chongª²Xiao, SHI Wei

    1Department of Neurosurgery, Second Hospital, Xi¡¯an Jiaotong University, Xi¡¯an 710004, China, 2Department of Pathology, Xi¡¯an Fourth Municipal Hospital, Xi¡¯an 710001, China

    ¡¾Abstract¡¿ AIM: To investigate the characteristics of cell apoptosis in cortex after mechanical white matter injury. METHODS: Twentyª²six SD rats suffering mechanical subcortical transection were killed at different time points postª²injury, and the brains were obtained. The change of cells in lesion area and cortex was observed by HE staining, bufferedª²methylen blue staining and TUNEL in situ endª²labeling. RESULTS: Histopathological examination showed neuronal necrosis and glial cell proliferation in lesion site, while many neurons withered in the layer ¢ò-¢õ of the corresponding cortex . Apoptotic neurons could be detected in the corresponding cortex as early as the 12th h postª²injury. The number increased with time, peaked during 5th-7th d, and then declined. In the 19th d, the apoptotic neurons still could be detected in the corresponding cortex, while few apoptotic neurons were found in lesion area, and the time was presented in a singleª²waveª²curve. CONCLUSION: The main pathological change of cortical neurons is not necrosis, but apoptosis after mechanical white matter injury. The apoptotic neurons are anatomically located in the corresponding cortical layer ¢ò-¢õ. ......