【摘要】 在用三碘季胺酚制动的大白鼠上进行实验。用玻璃微电极引导丘脑束旁核单位放电,观察伤害性电刺激坐骨神经时痛抑制神经元(简称Ⅰ神经元)的反应特点。我们的实验结果表明Ⅰ神经元的活动有以下特点:(1)较长的反应潜伏期。在13个Ⅰ神经元上的实验结果表明,反应潜伏期的平均值为203.8±137.8毫秒。(2)抑制性反应能持续较长的时间。在21个Ⅰ神经元上的实验结果表明,刺激坐骨神经所诱发的放电中止(即完全抑制)的持续时间有颇大的变动范围,最短为500毫秒,最长可达20秒。(3)较高的阈值,引起Ⅰ神经元抑制性反应所需的最低刺激强度为1.2毫安左右。(4)无适应性。重复刺激坐骨神经所诱发的Ⅰ神经元抑制性反应没有逐渐缩短的趋势。(5)时间总和。连续刺激坐骨神经可以使Ⅰ神经元抑制性反应的持续时间延长。根据以上结果可以认为痛抑制神经元具有与痛兴奋神经元类似的活动特点。更多还原

【Abstract】 The experiments were performed on albino rats immobilized by flaxedil.Theunit discharges of the nucleus Parafasicularis were led out with a glass microelectrodeand the neuron responses inhibited by noxious stimulation of the sciatic nerve wereexamined.The results obtained showed that the inhibition had characteristics as follows:(1)Long latent period.The mean of the latent period of 13 units was203.8±137.8 ms.(2)Long-lasting period.The shortest was 500 ms and the longest might reach-20s.(3)High threshold,In order to induce inhibition,the lowest intensity ofthe stimulus was 1.2 mA or so.(4)Poor adaptation.There was no sign of decrease in the duration ofinhibition induced by repetitive stimulations of the sciatic nerve.(5)Temporal summation.When the sciatic nerve was stimulated successively,the duration of inhibition was prolonged.It is evident that the characteristics of such neurons are similar to those ofthe neurons excited by noxious stimulation.更多还原