【摘要】 于清醒的肌肉麻痹的大鼠,用直流电分级阻滞法,以n=10或n=100的电脉冲刺激腓肠神经的不同传入纤维(分Ⅱ、Ⅱ+Ⅲ、Ⅲ、Ⅱ+Ⅲ+Ⅳ和Ⅳ类五组),观察刺激后即刻和10min时对中缝大核(NRM)神经元单位放电的影响。可见到(1)无论从引起兴奋的神经元数或反应的强度来看,均以细纤维的作用最大,粗纤维的作用最小,粗加细纤维居中。(2)Ⅲ类纤维的兴奋作用,短串脉冲大于长串脉冲。Ⅳ类纤维的兴奋作用,长串脉冲稍大于短串脉冲。(3)在刺激各组纤维后,所引起的反应,潜伏期有的较长;反应有的呈单相,有的呈兴奋和抑制的相互转化。上述结果为解决针刺或刺激神经镇痛的外周传入纤维问题提供了直接的实验依据。更多还原

【Abstract】 This study was carried out to determine what kind of afferent fibers was the most effectiveto activate neurons in nucleus raphe mapnus(NRM). Experiments were done on conscious butimmobilized rats. The effects of electrical stimulation of different afferent fibers (including groupⅡ, Ⅱ+ Ⅲ. Ⅲ, Ⅱ+ Ⅲ + Ⅳand Ⅳ fiber) in the sural nerve with short-train (n =10)or long-tr-ain (n =100) impulses on NRM unit discharge was observed immediately after stimulation and10 min later with graded direct current blockage. The results show:(1) The thin fibers (group Ⅲand Ⅳ) are the most effective, the thick fibers (group Ⅱ) are the lest effective and the effectsof Ⅱ+ Ⅲ and Ⅱ+ Ⅲ + Ⅳ are moderate according to either the number of excited neurons or theintensity of reactions neurons. (2) The excitatory effect of short -train impulses is more effec -tive than long- train impulses on group Ⅲ fibers. On group Ⅳ, however, the excitatory effectof long- train impulses is more effective than short-train impulses. (3) For some neurons, res-ponses occur after the first recording, that is, there is a relatively long latent period. On someneurons, there is transformation from excitatory to inhibitory responses or vice versa, that is, itis a diphasic response. Thus, these results provide direct experimental evidence to determinewhich peripheral fibers act a role in acupuncture analgesia and the analgesia of the stimulationof the peripheral nerve.更多还原