Gruen R J, Friedhoff A J, Coale A, Moghaddam B
Department of Psychiatry, New York University, NY 10003.
Brain Res. 1992 Dec 18;599(1):51-6. doi: 10.1016/0006-8993(92)90851-y.
At present, it is unclear whether ligands which bind at the benzodiazepine/GABA receptor complex play a tonic modulatory role with regard to striatal dopamine (DA) transmission. The present study was designed to examine the effects of Ro15-1788, a benzodiazepine (BZ) receptor antagonist, and SR 95531, a GABAA receptor antagonist, on striatal extracellular DA (DA[e]) concentrations in anesthetized and awake rats using the technique of in vivo microdialysis. Local administration of Ro15-1788 resulted in a dose-dependent increase in DA[e] in both anesthetized and awake animals. The Ro15-1788-induced increase in DA[e] was blocked by coadministration of the BZ agonist diazepam, as well as GABA. Local administration of SR 95531 also resulted in a dose-dependent alteration in striatal DA levels in both anesthetized and awake animals. The SR 95531-induced increase in DA was blocked by coadministration of GABA. The results suggest that GABA may play a tonic inhibitory role with regard to striatal DA transmission.
目前，尚不清楚在苯二氮䓬/GABA受体复合物上结合的配体对纹状体多巴胺（DA）传递是否发挥持续性调节作用。本研究旨在使用体内微透析技术，研究苯二氮䓬（BZ）受体拮抗剂Ro15 - 1788和GABAA受体拮抗剂SR 95531对麻醉和清醒大鼠纹状体细胞外DA（DA[e]）浓度的影响。在麻醉和清醒动物中，局部施用Ro15 - 1788均导致DA[e]呈剂量依赖性增加。Ro15 - 1788诱导的DA[e]增加被BZ激动剂地西泮以及GABA共同给药所阻断。局部施用SR 95531也导致麻醉和清醒动物的纹状体DA水平出现剂量依赖性变化。SR 95531诱导的DA增加被GABA共同给药所阻断。结果表明，GABA可能对纹状体DA传递发挥持续性抑制作用。
