猫脊髓后角浅层内GABA能神经终末与表达阿片μ受体神经元之间的突触联系

THE SYNAPTIC RELATIONSHIP BETWEEN GABAERGIC AXON TERMINALS AND NEURONS EXPRESSING μ OPIOID

为了研究ＧＡＢＡ与ＭＯＲ在吗啡镇痛中的相互关系，用包埋前免疫组织化学方法结合包埋后胶体金电镜技术，观察了猫脊髓后角浅层内γ－氨基丁酸（ＧＡＢＡ）能轴突终末与表达阿片μ受体神经元之间的突触联系。结果表明，后角浅层内约有三分之一的ＭＯＲ阳性树突和胞体与ＧＡＢＡ阳性终末形成突触连接，这些突触均为对称性突触。

The synaptic relationship between GABAergic axon terminals and neurons expressing μ opioid receptor(MOR)in the superficial spinal dorsal horn of the cat was examined by using pre embedding immunohistochemical method combined with post embedding immunogold technique.About one third of the cell bodies and dendrites showing MOR like immunoreactivity formed synaptic contacts with GABAergic axon terminals;all these synapses were symmetric.The present results suggest MOR positive neurons in the superficial layers of the cat spinal cord may be modulated by GABA releasing from presynaptic axon terminals.