Ambrose L M, Unterwald E M, Van Bockstaele E J
Department of Neurosurgery, Farber Institute for Neurosciences, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Anat Rec A Discov Mol Cell Evol Biol. 2004 Jul;279(1):583-91. doi: 10.1002/ar.a.20054.
Previous studies have shown significant changes in dopamine and opioid receptors in the basal ganglia following administration of cocaine. Cocaine administration results in a significant increase in the number of opioid receptors in dopamine-enriched brain regions. The aim of this study was to determine if dopamine D2 receptors (D2r) and micro-opioid receptors (microOr) are localized to the same neurons in the dorsolateral striatum. Immunoperoxidase and immunogold-silver labeling combined with electron microscopy was used to examine the ultrastructural localization of both receptors in the dorsolateral striatum. Approximately half of the microOr-labeled somatodendritic processes showed immunolabeling for the D2r. Similarly, about half of the D2r-labeled dendrites and cell bodies showed immunolabeling for the microOr. In conclusion, our results indicate that individual neurons in the rat dorsolateral striatum may be directly modulated by both dopaminergic and opioid ligands. These data also suggest that the molecular mechanism responsible for the up-regulation of microOrs in the caudate and putamen following cocaine exposure may depend, in part, on the co-existence of D2rs and micro-Ors in these cells.
先前的研究表明，服用可卡因后基底神经节中的多巴胺和阿片受体发生了显著变化。服用可卡因会导致富含多巴胺的脑区中阿片受体数量显著增加。本研究的目的是确定多巴胺D2受体（D2r）和微阿片受体（microOr）是否定位于背外侧纹状体的同一神经元。采用免疫过氧化物酶和免疫金银标记结合电子显微镜技术，研究了两种受体在背外侧纹状体中的超微结构定位。大约一半的微Or标记的树突状突起显示出D2r的免疫标记。同样，大约一半的D2r标记的树突和细胞体显示出微Or的免疫标记。总之，我们的结果表明，大鼠背外侧纹状体中的单个神经元可能受到多巴胺能和阿片配体的直接调节。这些数据还表明，可卡因暴露后尾状核和壳核中微Or上调的分子机制可能部分取决于这些细胞中D2r和微Or的共存。
