RT Journal Article SR Electronic T1 Opiate receptor agonists as modulators of gamma-aminobutyric acid turnover in the nucleus caudatus, globus pallidus and substantia nigra of the rat. JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 870 OP 877 VO 207 IS 3 A1 F Moroni A1 D L Cheney A1 E Peralta A1 E Costa YR 1978 UL http://jpet.aspetjournals.org/content/207/3/870.abstract AB The injection of various doses of morphine, subcutaneously, or of beta-endorphin, intraventricularly, changes the turnover rate of gamma-aminobutyric acid (TRGABA) in the substantia nigra, globus pallidus and nucleus caudatus. The TRGABA decreases in N. caudatus but increases in globus pallidus and substantia nigra. These changes are dose related and can be inhibited by naltrexone. The increased TRGABA in globus pallidus elicited by these opioid receptor agonists may be associated with catalepsy since muscimol, a specific GABA receptor agonist, injected into the globus pallidus causes a dose-related catalepsy. Since this GABA receptor agonist injected into the substantia nigra fails to cause catalepsy, one can exclude that the increase in the TRGABA of substantia nigra elicited by opiate receptor agonists is operative in mediating the catalepsy elicited by opioids.