title: Effect of delta 9-tetrahydrocannabinol on circling in rats induced by intranigral muscimol administration.
abstract: Unilateral injection of 25 ng of muscimol into the rat substantia nigra pars reticulata induced contralateral circling. Circling induced by 25 ng of muscimol was increased by simultaneous administration of 1 microgram of delta 9-tetrahydrocannabinol and abolished by 10 micrograms. Previous experiments have shown that delta 9-tetrahydrocannabinol enhances muscimol-induced catalepsy in the globus pallidus. These results identify another brain area in which synergism between delta 9-tetrahydrocannabinol and muscimol can occur and show that delta 9-tetrahydrocannabinol can enhance an excitatory as well as inhibitory GABAergic motor effect. The data support the hypothesis that cannabinoids can facilitate transmission along central gamma-aminobutyric acid (GABA) releasing pathways.
mesh_terms: D000818:Animals; D013759:Dronabinol / Q000494:pharmacology*; D008845:Microinjections; D009043:Motor Activity / Q000187:drug effects*; D009118:Muscimol / Q000494:pharmacology*; D011136:Polysorbates / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013378:Substantia Nigra / Q000187:drug effects*
chemical_list: D011136:Polysorbates; D009118:Muscimol; D013759:Dronabinol