大鼠扣带回前部对外侧缰核单位放电的抑制作用

电刺激扣带回前部,对75％的外侧缰核痛兴奋神经元(pain-excitative neuron of lateral habenular nucleus,LHPE)和75％的痛抑制神经元(pain-inhibitive neuron of lateral habenular nucleus,LHPI)的自发放电均产生抑制作用,并取消躯体和内脏伤害性刺激对外侧缰核(lateral habenular nucleus,LHN)单位放电的影响。扣带回内微量注射吗啡可以抑制LHPE的自发放电,并取消伤害性刺激对LHPE的增频效应。注射纳洛酮则使LHPE的自发放电增多,加强伤害性刺激对LHPE的增频作用,并可拮抗电针对LHPE伤害性刺激反应的抑制作用。

INHIBITORY EFFECT OF CINGULATE GYRUS ON UNIT DISCHARGES OF NEURONS IN LATERAL HABENULAR NUCLEUS

Experiments were performed on 48 rats immobilized with flaxedil. The spontaneous discharges of 75 percent of both pain-excitative neurons (LHPE) and pain-inhibitive neurons (LHP1) of lateral habenular nucleus were inhibited by electrical stimulation of the anterior region of cingulate gyrus.The effect of somatic and visceral noxiou; stimulation on unit discharges of lateral hii-benular nucleus (LHN) could be inhibited by stimulation of the anterior region of cingulate gyrus.Microinjcction of morphine into the anterior region of cingulate gyrus could inhibit the spontaneous discharges of LHPE and suppress their responses to somatic and visceral noxious stimulation.Microinjection of naloxone into the anterior region of cingulate gyrus increased the frequency of spontaneous discharges of LHPE and intensified their responses to somatic and visceral noxious stimulation. Microinjection of naloxone could also cancel out the inhibitory effect of electro-acupuncture on the nociceptive responses of LHPE.