猫SI、SII对尾核痛相关单位的下行调制作用初探

A Preliminary Study of the Descending Modulating from Somatosensory Areas Ⅰ and Ⅱ on Pain Relating Units of Caudate Nucleus in Cat

实验用清醒麻痹猫进行观察。结果表明,刺激SⅠ区,尾核头部痛相关单位多数受到抑制。36.36％的单位在刺激SⅠ区后表现先抑制后兴奋的现象。64.29％的单位在刺激SI区后出现抑制效应时,单位放电即刻停止一定时间。刺激SⅡ区的效应与刺激SⅠ区类同。用GABA改变SⅡ区的正常机能状态,刺激SⅠ区的效应,在26个痛相关单位中有13个单位显示激活或相反,而对照组没有改变。提示SⅠ区对痛相关单位有单独的抑制效应。而在SⅠ区对尾核头部痛相关单位的下行调制中SⅡ区起一定的协同作用。

Experiments were performed on 41 conscious paralyzed cats. Results srowed that when the somatosensory area Ⅰ(SⅠ)was stimulated most pain relating units inhibited. About 36.36% of the units(8/22) showing excitatory effects after stimulating SI had a phenomenon of being inhibited initially and excited subsequently(inhibiting time 4.21±0.75sec). About 64.29% of the units(36/56) showing inhibitory effects after stimulating SⅠ had a phenomenon of that the discharges of the units stopped immedtely for a period of time(6.75±1.62sec). The effects of stimulating SⅡ were similar to that of SⅠ when the state of normal function of SⅡ had been changed by applying GABA on it, effects of stimulating SⅠ were as follow: of 26 pain units, 13 units showed activation or catrary; while the effects of control group remained uncharged. These results indicate that SⅠ has an inhibitory effects solely on pain relating units and SⅡ plays a certain role in presence of the descending modulation from SⅠ on pain relating units in the head of caudate nucleus of the cat.