【摘要】 为了研究大脑皮层体感Ⅰ区与痛觉以及针刺镇痛作用的关系,以钾离子透入下肢皮肤作为痛刺激,以操作式条件反射作为痛指标,用钨丝微电极记录大脑皮层体感Ⅰ区单个神经元的电活动,在10只清醒、可以活动的猴子上进行了实验观察。在下肢的皮层代表区分离和记录了能对不同传入刺激起反应的神经元215个。28个对皮肤伤害性刺激起反应。其中25个发放增加(兴奋型神经元),3个发放减少(抑制型神经元)。对12个伤害性神经元进行了针刺效应的观察。在针刺过程中有6个神经元(4个兴奋型、2个抑制型)对伤害性刺激的反应受到抑制。其中有些神经元的抑制可伴有痛阈的升高,但两者未呈现严格的平行关系。皮层体感Ⅰ区中亦可记录到会聚性神经元,即同一神经元既可接受皮肤机械刺激,亦可接受皮肤伤害性刺激。其中有些神经元对于不同性质的刺激可以出现不同型式的反应,如对钾离子刺激皮肤出现抑制性反应而对触觉刺激出现兴奋性反应。针刺时,往往只有伤害性刺激引起的反应受到抑制,而机械刺激引起的反应没有明显变化。实验表明,针刺可以使皮层体感Ⅰ区的某些神经元对皮肤伤害性刺激的反应减弱;但是这种效应可能不是发生在皮层本身,而是续发于皮层下结构活动的变化。更多还原

【Abstract】 Experiments were performed on 10 conscious;movable rhesus monkeys(Ma-caca mulatta)to study the relationship between the somatosensory area Ⅰ(SI)ofthe cerebral cortex and the elaboration of pain sensation and acupuncture analge-sia.Operant conditioning elicited by noxious stimulation which was produced bypotassium iontophoresis in the skin of the leg was taken as an indication of pain,and the single unit activity in the leg representation area of SI was recorded simul-taneously with a tungsten microelectrode.A total of 48 penetrations was madeand 215 neurons responding to afferent inputs of various sensory modalities wereisolated and studied.There were only 28 neurons responding to noxious stimula-tion,of which 25 were excitatory,and 3 inhibitory.The effect of acupuncturewas observed on 12 nociceptive neurons.During acupuncture,the nociceptiveresponse was inhibited in 6 neurons(4 excitatory,2 inhibitory),and an elevationof pain threshold was found simultaneously in some cases,but no strictly parallelcorrelationship could be observed between them.Multimodal neurons were also found in SI.Some of the neurons were ableto respond to both light mechanical and noxious stimulations,but the patternsof the unit discharge were in some cases different in response to different kindsof stimulation.For 7 of these cells,both the light mechanical and noxious stimuliwere excitatory,while 5 were activated by the former and inhibited by the latter.During acupuncture,only the nociceptive response was inhibited while the me-chanoreceptive response of the same neuron appeared little changed.The experimentaI resuIts showed that the nociceptive response of the neuronsin SI of the cerebral cortex could be inhibited by acupuncture,and this effect ofacupuncture might not be directly exerted on the cerebral cortex itself,but by wayof subcortical centers.更多还原