【摘要】 本实验以皮肤伤害性刺激引起的回避性操怍式条件反射作为外周皮肤痛指标,在七只清醒、可以活动的猕猴身上观察了同时皮层内刺激SⅠ区和SⅡ区对外周痛阈的影响,其结果如下:(1)在单独刺激SⅠ区或SⅡ区后肢代表区观察到对侧后肢皮肤相应感受野痛阈明显升高后,同时刺激SⅠ及SⅡ区的47次实验中,有31次可见痛阈比单独刺激SⅠ或SⅡ区痛阈进一步有不同程度的升高;13次其痛阈未见进一步升高;3次其痛阈反而下降。(2)单独刺激SⅠ区后肢代表区,对同侧外周皮肤感受野痛阐没有影响,单独刺激SⅡ区的后肢代表区,则可使同侧相应外周感受野痛阈明显升高,而同时刺激SⅠ区和SⅡ区的8次实验中有7次发现同侧肢体皮肤感受野痛阈也进一步升高。(3)10次单独刺激SⅠ或SⅡ区,均未见非感受野皮肤痛阈明显改变,同时刺激SⅠ和SⅡ区也未见其痛阈有明显影响。相反10次同时刺激SⅠ和SⅡ区的手代表区也未发现对后肢皮肤痛阈有明显影响。结果提示:两个体感区对上行痛觉信息的相互间的调制作用主要表现为加强对外周痛阈的抑制作用。更多还原

【Abstract】 The effect of simultaneous intracortical microstimulation of SⅠ and SⅡ upon peripheral pain threshold was observed in conscious movable rhesus monkeys (Macaca Mutatta). Operant conditioning elicited by noxious stimulation was taken as an indicator of pain. Tungsten mi-croelectrodes were used both for recording the single unit activity and intracortical stimulation. The results obtained were as follows: (Ⅰ) In 31 out of 47 tests of simultaneous intracortical stimulation of SⅠ and SⅡ the pain threshold in contralateral corresponding receptive field of the skin was elevated more greatly; 13 out of 47 tests, the pain threshold was not elevated; 3 out of 47 tests, the pain threshold was lowered. (2) In 7 out 8 tests, the pain threshold in ipsi-lateral corresponding receptive field was changed by alone stimulation of posterior limb representation of SⅡ, but not in SⅠ. During simultaneous stimulation of SⅠ and SⅡ the pain threshold in ipsila:eral receptive field was also elevated obviously. In 10 tests, the pain threshold in non-receptive field was not changed by alone stimulation of SI or SⅡ, and the pain threshold was not also changed during simultaneous stimulation of two areas. In 10 tests, pain threshold of skin in contralateral posterior limb was not also changed during simultaneous stimulation of hand representation of SⅠ and SⅡ. The results show that the modulation between SⅠ and SⅡ on ascending message of painful sensation appears mainly to strengthen the inhibiting effect of perpheral pain threshold.更多还原