Article date: 1987/1/1
PubMed ID: 3035084
Journal name: Journal of neural transmission (ISSN: )
Changes in the endogenous GABA concentration and in GABA turnover following GABA receptor stimulation or blockade were studied in the substantia nigra and the corpus striatum of the rat. The GABA agonists, muscimol, baclofen and THIP decreased the accumulation of GABA following inhibition of GABA-alpha-ketoglutaric acid aminotransferase by gamma-acetylenic GABA (GAG) in both structures investigated. Only the effect of muscimol in the substantia nigra was inhibited by the GABA antagonist, bicuculline. Muscimol, baclofen and progabide reduced the disappearance rate of GABA in the substantia nigra following inhibition of the glutamate decarboxylase by 4-deoxypyridoxine. The endogenous GABA concentration was decreased in the corpus striatum following muscimol, THIP or baclofen, probably due to a decreased synthesis of GABA. Smaller effects were seen on the endogenous GABA concentration in the substantia nigra, since both the synthesis and the utilization of GABA were decreased by muscimol and baclofen. Thus, the turnover of brain GABA might be regulated by changes in receptor activity.
Author List: Lindgren S
Publication Types: Journal Article; Research Support, Non-U.S. Gov't
Substances mentioned in the article: Alkynes; Aminocaproates; Isoxazoles; Receptors, GABA-A; Picrotoxin; Muscimol; progabide; gamma-Aminobutyric Acid; 4-amino-5-hexynoic acid; Baclofen; gaboxadol; Bicuculline;
Mesh terms: Alkynes; Aminocaproates/pharmacology; Animals; Baclofen/pharmacology; Bicuculline/pharmacology; Corpus Striatum/metabolism; Isoxazoles/pharmacology; Male; Muscimol/pharmacology; Picrotoxin/pharmacology; Rats; Rats, Inbred Strains; Receptors, GABA-A/physiology; Substantia Nigra/metabolism; gamma-Aminobutyric Acid/analogs & derivatives;