摘要
本研究用免疫组织化学双重染色技术，对伏核内５羟色胺（５ＨＴ）样免疫组织化学染色阳性终末与甲硫氨酸脑啡肽（ＭｅｔＥＮＫ）样阳性神经元之间的直接突触联系进行了观察。在光镜下观察到５ＨＴ样阳性纤维和终末位于伏核吻尾向全长的各部，尤以尾段的内侧部和腹侧部较密集，但未见５ＨＴ样阳性神经元；ＭｅｔＥＮＫ样阳性神经元的胞体、纤维和终末也主要分布于伏核的内侧部和腹侧部，但数量较少。在电镜下观察到５ＨＴ样阳性终末与ＭｅｔＥＮＫ样阳性神经元的胞体和树突形成以非对称性为主的轴体和轴树突触。以上结果为来自中脑的５ＨＴ能上行纤维与伏核内ＭｅｔＥＮＫ能神经元之间以串联联系方式发挥镇痛作用提供了形态学依据。
The immunohistochemical double staining technique was used in the present study to investigate the synaptic connections between serotonin like immunoreactive (5 HT LI) terminals and methionine enkephalin like immunoreactive (Met ENK LI) neurons in the nucleus accumbens (Acb) of the rat. Under the light microscope, 5 HT LI fibers and terminals were located over the whole rostrocaudal extents of the Acb, but mainly in the medial and ventral regions at the caudal level of the Acb. There were no 5 HT LI neuronal cell bodies within the Acb. A few Met ENK LI neuronal cell bodies, fibers and terminals were also mainly found in the medial and ventral regions at the caudal level of the Acb. Under the electron microscope, 5 HT LI terminals were mainly observed to form asymmetrical axo dendritic synapses with the dendrites of Met ENK LI neurons. The present results provide morphological evidence that 5 HT released in the Acb by ascending serotoninergic fibers originated from midbrain might in turn activate an enkephalinergic mechanism within the Acb, which may play a role in the neural circuitry for antinociceptive effect.
出处
《中国疼痛医学杂志》
CAS
CSCD
1999年第1期31-35,共5页
Chinese Journal of Pain Medicine
基金
国家杰出人才基金资助
关键词
伏核
脑啡肽
中脑边缘
镇痛环路
血清素
Nucleus accumbens
Serotonin
Methionine enkephalin
Mesolimbic antinociceptive loop
Rat
