关键词: GABA;受体，阿片样，μ;水管周灰质;显微镜检查，共焦;免疫组织化学;大鼠

    摘 要:目的 观察中脑导水管周围灰质(PAG)内是否存在γ-氨基丁酸(GABA)与阿片μ受体(MOR)共存神经元. 方法 免疫荧光组织化学双重染色技术，染色结果在激光扫描共聚焦显微镜下观察. 结果 GABA阳性神经元主要见于PAG中、尾段内侧区和腹外侧区，阳性神经元多散在分布并多为小型，中型者较少;散在分布的MOR阳性神经元主要见于PAG中、尾段的腹外侧区，多为中、小型神经元;散在并同时呈GABA和MOR双重染色阳性的中、小型神经元主要见于PAG中、尾段的腹外侧区. 结论 PAG内有GABA与MOR共存的神经元，提示内源性阿片物质对PAG内的GABA能神经元可能有调控作用.

    Co┐existence of GABA andμopioid receptor in neu┐rons of the midbrain periaqueductal gray in the rat

    DONG Yuan-Xiang，CHEN Tao，LI Yun-Qing

    Department of Anatomy&K.K.Leung Brain Re-search Centre，Fourth Military Medical University，Xi'an710033，China

    Keywords:GABA;receptors，opioid，mu;periaqueductal gray;microscopy，confocal;immunohis-tochemistry;rats

    Abstract:AIM To observe whetherγ-aminobutyric acid(GABA)andμopioid receptor(MOR)co-exist in neurons of the periaqueductal gray(PAG)in the rat.METHODS Im-munofluorescent histochemical double-staining technique was used.The staining results were observed with laser scanning confocal microscope.RESULTS GABA-immunoreactive(GABA-IR)neurons were mainly seen in the medial and ven-trolateral subregions at the middle and caudal levels of the PAG.Most of the sparsely distributed GABA-IR neurons were small-sized and the number of medium-sized GABA-IR neurons was small.Scattered MOR-IR neurons were mainly observed in the ventrolateral subregion at the middle and cau-dal levels of the PAG.Most of the MOR-IR neurons were small-and medium-sized.Small-and medium-sized neurons simultaneously showing both GABA-IR and MOR-IR were scattered in the ventrolateral subregion at the middle and cau-dal levels of the PAG.CONCLUSION There are GABA and MOR co-existing neurons in the PAG.The present results suggest that endogenous opioid-like substances might regu-late GABAergic neurons in the PAG. ......