自从1975年杜焕基等报导损毁中缝大核(NRM)后明显减弱针刺镇痛效应

Oliveras等报导刺激NRM可产生明显镇痛和Proudfit等报导损毁NRM减弱吗啡镇痛效应以来

围绕着NRM在痛觉调制中的作用

国内外许多学者进行了广泛的研究

Mayer等和Fields等分别于1976年和The article reviews the main results of recent years study on the relationship between neurons in nucleus raphe magnus(NRM)and moving reflex evoked by noxious stimulation

including:1.Relative phasic discharge frequency change of on-cell and off-cell in NRM occurred when tail-flick reflex(TF)evoked by noxious stimulation.The relative phasic activaty of on-cell and off-cell in NRM was deerased or lost when TF was inhibited by brain stimulation and morphine analgesia.The data suggested that on-cell and off-cell in NRM participated in descending inhibition on spinal cord.2.The initial EPSPS on neurons of NRM always occurs after the initial digastric EMG elieited by tooth pulp shock.3.there is a positive feedback loop of reciprocal excitation befween descending pathway ftom NRM and ventral horn neurons projecting to NRM of spinal cord.It was suggested that motor neuron pool in spinal cord possible involved in the mechanism of descending inhibition from the NRM.