Zhang Ke-Xue, Zhao Jia-Jia, Chai Wei, Chen Ji-Ying
Department of Pediatric Surgery, Chinese PLA General Hospital, Beijing, China.
Department of Anesthesiology, Shunyi District Hospital, Beijing, China.
Neural Regen Res. 2021 Apr;16(4):744-749. doi: 10.4103/1673-5374.295346.
Spinal cord injury dramatically blocks information exchange between the central nervous system and the peripheral nervous system. The resulting fate of synapses in the motor cortex has not been well studied. To explore synaptic reorganization in the motor cortex after spinal cord injury, we established mouse models of T12 spinal cord hemi-section and then monitored the postsynaptic dendritic spines and presynaptic axonal boutons of pyramidal neurons in the hindlimb area of the motor cortex in vivo. Our results showed that spinal cord hemi-section led to the remodeling of dendritic spines bilaterally in the motor cortex and the main remodeling regions changed over time. It made previously stable spines unstable and eliminated spines more unlikely to be re-emerged. There was a significant increase in new spines in the contralateral motor cortex. However, the low survival rate of the new spines demonstrated that new spines were still fragile. Observation of presynaptic axonal boutons found no significant change. These results suggest the existence of synapse remodeling in motor cortex after spinal cord hemi-section and that spinal cord hemi-section affected postsynaptic dendritic spines rather than presynaptic axonal boutons. This study was approved by the Ethics Committee of Chinese PLA General Hospital, China (approval No. 201504168S) on April 16, 2015.
脊髓损伤会显著阻断中枢神经系统与周围神经系统之间的信息交流。运动皮层中突触的最终命运尚未得到充分研究。为了探究脊髓损伤后运动皮层中的突触重组，我们建立了T12脊髓半横断小鼠模型，然后在体内监测运动皮层后肢区域锥体神经元的突触后树突棘和突触前轴突终扣。我们的结果表明，脊髓半横断导致运动皮层两侧的树突棘重塑，且主要重塑区域随时间变化。它使先前稳定的棘突变得不稳定，并消除了更不可能重新出现的棘突。对侧运动皮层中的新棘突显著增加。然而，新棘突的低存活率表明新棘突仍然脆弱。对突触前轴突终扣的观察未发现显著变化。这些结果表明脊髓半横断后运动皮层中存在突触重塑，且脊髓半横断影响突触后树突棘而非突触前轴突终扣。本研究于2015年4月16日获得中国人民解放军总医院伦理委员会批准（批准号：201504168S）。
