大鼠脊髓缺血再灌流时脊髓神经元对躯体和内脏传入刺激的反应

５０只大鼠用乌拉坦麻醉，箭毒制动。通过阻断腹主动脉血流以模拟腰段脊髓的局部缺血和再灌流损伤，玻璃微电极记录Ｌ２节段脊髓单位放电（ＳＣＵＤｓ），观察缺血再灌流时脊髓神经元对腓神经刺激（ＰＮＶ），内脏大神经刺激（ＶＬＮＶ）及两者同时刺激（ＳＶ）的反应。结果在缺血前所记录的１３３个自发放电单位中，对３种刺激均产生兴奋（Ｅ）、抑制（Ｉ）及无反应（ＮＲ）３种形式的反应，表明大鼠Ｌ２节段脊髓存在躯体、内脏和躯体内脏反应性神经元，并有会聚和阻塞现象。在脊髓缺血再灌流时，神经元对ＰＮＶ、ＶＬＮＶ、ＳＶ也产生Ｅ、Ｉ、ＮＲ３种形式的反应，提示脊髓缺血再灌流时神经元对躯体和内脏传入刺激的反应形式不受影响；但缺血时ＳＣＵＤｓ对ＰＮＶ、ＶＬＮＶ产生反应的单位数减少，这表明脊髓缺血损伤时神经元对躯体和内脏传入刺激的反应性减弱，随着缺血损伤加重，脊髓神经元对躯体内脏信号的整合功能下降

Effects of ischemia and reperfusion on changes of responses of neurons in spinal cord to somatic and visceral afferent volleys in rats

After the model of local ischemia and reperfusion in the lumbar part of the spinal cord was established by occlusion of the abdominal aorta (AA) in 50 Wistar rats anesthetized with urethane and braked with curare, the spinal cord unit discharges (SCUDs) in L 2 spinal cord was recorded with the glass microelectrode to investigate the responses of the neurons to peroneal nerve volley (PNV), visceral large nerve volley (VLNV) and simultaneous volleys of both kinds (SV). From the analysis of the records of 133 SCUDs, it was found that there were three kinds of responses of neurons, namely, excitation (E), inhibition (I) and non reponse (NR) in L 2 spinal cord to all the three kinds of volleys after AA occlusion and reperfusion. These findings suggest that there are neurons responsive to somatic, visceral and viscerosomatic afferent volleys in L 2 spinal cord and ischemia and reperfusion do not significantly affect the forms of responses of the neurons to the three kinds of volleys. Whereas the fact that SCUDs responsive to PNV and VLNV were decreased under ischemic state suggests that ischemia reduces the reactivity of neurons to somatic and visceral afferent volleys.