Swim-induced grooming in mice is mediated by a dopaminergic substrate

Summary Grooming induced in mice after a period of swimming was potently and dose-dependently blocked by neuroleptics. The order of potency of the neuroleptics was spiroperidol>haloperidol>cis-flupenthixol>pimozide>chlorpromazine>thioridazine. The trans isomer of flupenthixol was inactive at 40M/kg. The-adrenergic receptor antagonists, phentolamine and phenoxybenzamine, and the catecholamine synthesis inhibitor,-methyl-p-tyrosine were essentially without effect on the grooming behaviour. Amitriptyline inhibited grooming behaviour only in doses which severely affected the animals motor function. Fluoxetine was without effect. Cisflupenthixol was less active in inhibiting grooming in animals chronically treated with haloperidol than in control animals, indicating the presence of supersensitive dopamine receptors. The data indicate that swim-induced grooming in mice is mediated via dopaminergic systems.