NEURO-PHARMACOLOGICAL SPECTRUM OF MUSCIMOL

Muscimol was tested in comparison with a series of reference compounds in a variety of situations in which GABA-related drugs are known to have an effect. Muscimol blocked the convulsions and/or lethality due to picrotoxinin, strychnine and a low dose of bicuculline. It was inactive against higher dosis of bicuculline, metrazole or electroshock convulsions. Muscimol reduced both the basal and the picrotoxin-induced multi-unit activity of the neurons of the dorsal Deiters' nucleus ; although active at low doses, the maximum effect of muscimol was relatively weak. Muscimol potentiated neuroleptic-induced catalepsy, and this effect was bicuculline sensitive ; it did not induce catalypsy in the presence of sulpiride. At high doses muscimol blocked apomorphine-induced stereotyped behaviour. It is proposed that muscimol is a GABA agonist of high affinity but of relatively low efficacy as based on its spectrum of neuropharmacological activities in vivo". © 1979."