强啡肽对纹状体内D_1多巴胺受体反应的调节

用6-羟多巴胺破坏黑质纹状体通路，使大鼠多巴胺耗竭后，应用原位杂交组织化学方法测量D1多巴胺受体对即早基因c－fos和zif268诱导反应，分析强啡肽对突触前、后调节作用。先用D1多巴胺受体激动剂SKF－38393反复处理动物，促进纹状体内强啡肽表达，在伏隔核强啡肽表达增加，同时伴随着即早基因c-fos和zif268的减少．在纹状体的背部和两侧，强啡肽表达虽大量增加，而D1多巴胺受体反应仍然维持原水平．在中央纹状体区，即早基因的表达处于中间水平。结果提示，纹状体内强啡肽起着调节多巴胺输入到纹状体黑质神经元的作用，包括突触前、后位置；并且调节作用在纹状体的腹、背侧区是不同的

THE REGULATION OF DYNORPHIN TO D_1 DOPAMINE RECEPTOR RESPONSES IN THE STRIATUM

We analysed the regulation of dynophin to pre-and postsynaptic effects after striatal dopamine depletion by 6-OHDA lesion of the nigrostriatal pathway. D1-receptor-mediated immediate-early gene induction was measured by using in situ. hybridization histochemistry.Firstly, the animals were repeatedly treated with the D1-receptor agonist SKF-38393 to increase dynorphin levels in rats with dopamine depletions. In the nucleus accumbens, increased dynorphin expression was accompanied by reduced induction of the immediate-early genes c-fos and zif 268 by SKF-38393. On the contrary, in dorsal and lateral aspects of the dopamine-depleted striatum, this D1 response was sustained in spite of a large increase in dynorphin expression. In the central striatum, intermediate changes for both dynorphin expression and immediate-early gene induction by D1-receptor activation are observed. The results indicate that dynorphin in the striatum functions to regulate dopamine input to striatonigral neurons. acting at both pre-and postsynaptic sites and that the effects differ between dorsal and ventral striatal regions.