Influence of baclofen and GABA-minetic agents on spontaneous and olfactory-bulb-ablation-induced muricidal behaviour in the rat.

Effects of baclofen, 5-aminomethyl-3-hydroxyisoxazol (muscimol) and GABA-cetylester on spontaneous and olfactory bulb-ablation-induced muricidal behaviour in rats was investigated. At doses of 3--10 mg/kg i.p. baclofen inhibited the killer reaction in spontaneous and lesioned rats to the same extent. In contrast, muscimol (0.75--1.5 mg/kg i.p.) and GABA-cetylester (10--50mg/kg i.p.) depressed markedly only the spontaneous muricidal response. These findings suggest a possibility that muscimol and GABA-cetylester exert their inhibitory action through an activation of GABA-neurons localized in the bulbus olfactorius, whereas baclofen appears to affect also neuronal systems outside this nervous structure.