Sperber E F, Wurpel J N, Sharpless N S, Moshé S L
Department of Neurology, Albert Einstein College of Medicine, Bronx, NY 10461.
Pharmacol Biochem Behav. 1989 Apr;32(4):1067-70. doi: 10.1016/0091-3057(89)90083-x.
Concentrations of striatal dopamine (DA), serotonin (5-HT) and their metabolites were measured following infusions of the GABAA receptor agonist, muscimol, or GABAA receptor antagonist, bicuculline, into the substantia nigra (SN) or areas dorsal to the SN in adult rats and 16-day-old rat pups. Results indicated that intranigral infusions of muscimol produced site-specific increases in the concentrations of striatal DA metabolites in adults, while in pups, intranigral muscimol infusions produced site-specific increases in the concentrations of striatal DA. Intranigral infusions of bicuculline had no effect on striatal DA or its metabolites in either age group. Neither GABAergic drug had any effect on striatal 5-HT or its metabolite. The data suggest that the effect of nigral GABAA agonist infusions on the activity of the nigrostriatal pathway is age-specific. The lack of opposing effects following the nigral infusion of a GABAA receptor antagonist indicates that the influences of GABAA agonists may be mediated by different mechanisms as a function of age.
在成年大鼠和16日龄幼鼠的黑质（SN）或SN背侧区域注射γ-氨基丁酸A（GABAA）受体激动剂蝇蕈醇或GABAA受体拮抗剂荷包牡丹碱后，测量纹状体多巴胺（DA）、血清素（5-HT）及其代谢产物的浓度。结果表明，向成年大鼠黑质内注射蝇蕈醇会使纹状体DA代谢产物浓度出现位点特异性增加，而在幼鼠中，向黑质内注射蝇蕈醇会使纹状体DA浓度出现位点特异性增加。向黑质内注射荷包牡丹碱对两个年龄组的纹状体DA或其代谢产物均无影响。两种GABA能药物对纹状体5-HT或其代谢产物均无任何影响。数据表明，黑质内注射GABAA受体激动剂对黑质纹状体通路活性的影响具有年龄特异性。黑质内注射GABAA受体拮抗剂后缺乏相反作用表明，GABAA受体激动剂的影响可能因年龄不同而通过不同机制介导。
