【摘要】 为了研究皮层体感Ⅰ区(S_Ⅰ 区)在痛觉的产生和调制以及在针刺镇痛中的作用,以皮肤伤害性刺激引起的操作式条件反射为痛指标,用钨丝微电极记录神经元的电活动和进行皮层内刺激,并用冰盐水进行皮层局部阻滞,在10只清醒的、可以活动的猕猴上进行了实验观察。刺激皮层 S_Ⅰ 区对感受野部位皮肤痛阈可产生明显的影响。在51次实验中有46次引起了痛阈的变化,仅有5次未见明显的变化。在13次对非感受野的皮肤痛阈的影响的实验中,10次未见变化,仅有3次出现轻度变化。皮层内刺激效应往往在刺激开始就出现,并延续到刺激的全过程。停止刺激后痛阈的恢复约需4—6分钟。皮层内刺激对针刺镇痛效应的影响与其对皮肤痛阈的影响有极为密切的关系,即皮层内刺激使皮肤痛阈下降者往往是对抗针刺的镇痛效应,而使皮肤痛阈升高者往往是加强针刺的镇痛效应。在12次冷冻皮层 S_Ⅰ 区的实验中全部都表现为使感受野皮肤痛阈的升高。去冷冻后约需3—8分钟才由抑制状态回复到原来水平。而对非感受野皮肤痛阈影响的8次实验中,有6次没有产生任何影响。本实验的结果表明,皮层体感区对痛觉是有一定的调制作用,当其受到电刺激或冷冻阻滞时,均可使相应部位的皮肤痛阈降低或升高,同时还能对抗或加强针刺的镇痛效应。更多还原

【Abstract】 The purpose of this investigation was to clarify whether the somatosensoryarea I(SI)of the cerebral cortex might play a role in elaboration and modulationof pain sensation and acupuncture analgesia.Experiments were prefbrmed on 10conscious,movable rhesus monkeys(Macaca mulatta).Operant conditioning eli-cited by noxious stimulation was taken as an indicator of pain.Tungsten mi-croelectrodes were employed both for recording the single unit activity extracellularly and for inractortical stimulation.In some cases,ice-saline was applied to the surfaceof the cerebral cortex to induce a reversible decortication locally.The effect of intracorfical stimulation of SI upon peripheral pain threshold wasobserved.In the majority of the sessions(42 out of 47),the pain threshold changedgreatly in the corresponding receptive fields of the skin during intracortical stimu-lation,but the threshold remained unchanged in non-receptive fields in most ses-sions(10 out of 13).This effect usually lasted for 4 to 6 minutes after the ces-sation of stimulation.It was found that the analgesic-effect of acupuncture was.greatly altered when intracortical stimulation Was applied simultaneously.Therewas a close relationship between the effect of intracortical stimulation on the acu-puncture analgesia and that on the pain threshold in peripheral receptive fields.The analgesic effects of acupuncture were usually weakened or even abolished by in-tracortical stimulation if the latter applied alone gave rise to a facilitating effect onthe pain threshold.On the other hand,the acupuncture analgesia was en-hanced if the intracortical stimulation applied alone exerted an inhibitory effecton the pain threshold.The pain threshold in the corresponding receptive fields was elevated obvious-ly during the application of ice-saline to the SI.This inhibitory effect usually last-ed for 3 to 8 minutes after the withdrawal of the ice-saline.But the pain thres-hold in the non-receptive fields was not changed in most sessions(6 out of 8).The present study showed that the pain sensation could be modulated by so-matosensory area I of the cerebral cortex.During stimulating or cooling the cere-bral cortex,both the pain threshold in the peripheral receptive fields and the anal-gesic effect of acupuncture could be altered obviously.更多还原