刺激家兔额叶皮层影响尾核痛单位放电机制的初步探讨

EFFECT OF STIMULATING FRONTAL CORTEX ON PAIN UNITS OF CAUD ATE NUCLEUS AND PRELMINARY EXPLORE OF PROBALE MECHANISM

目的：探讨额叶皮层对尾核痛单位放电的影响及其可能机制。方法：参照Ｓａｗｙｅｒ兔脑图谱，用ＳＮ－２型推进器以２μｍ／ｓ速度将玻璃微电极插入尾核头部Ａ３～５，Ｒ３．５～５，Ｈ３．５～５处引导神经元自发放电。结果：引导了尾核单位放电３７９个，其中痛单位８６个，占引导总数的２２．６８％，包含痛兴奋单位（ＰＥＮ）５７个，占痛单位的６６．２８％；痛抑制单位（ＰＩＮ）２９个，占３３．７２％。尾核有７４．４２％的痛单位对刺激额叶皮层起反应。刺激额叶皮层可易化尾核ＰＩＮ的电活动（６２．５２％出现增频反应），抑制ＰＥＮ的电活动（６４．９１％出现减频反应）。脑室注射阿托品或氟哌啶醇均可不同程度的阻断刺激额叶皮层对尾核痛单位的影响。结论：额叶皮层参与对尾核痛单位的调制，乙酰胆碱。

Objective:This study investigated the effect of stimulating the frontal cortex(FC) on the pain units of the anterior part of caudate nucleus and probable mechanism in conscious paralytic rabbits Methods:Refered to 《Sawyer's:The rabbit diencephalon in stereotaxic coordinates》,putting grass microelectrodes into A 3￣5 ,R 3 5￣5 ,H 3 5￣5 of the anterior part of caudate nucleus in 2 μm/s by SN 2 to conduet discharges of neurons Results:The pain units of caudate nucleus are amounted to 22 68% of the neurous recorded,74 42% of these pain units responded to FC stimulation.When stimulated FC,64 91% of the discharge electric frequency of PEN were decreased and 65 52% of PIN were increased This effect was contrary on the effect of nerve peronaers communis,FC stimulation produced inhibition on PEN and produced excitation on PIN of caudate nucleus This effect was blocked by intraventriclar injection of atropine(100 μg in 30 μl) or haloperidol(100 μg in 30 μl) Conclusion:FC takes part in the modulation of the pain units of caudate necleus;and cholinergic, dopamine and their receptors are possibly involved in such mechanism