CENTRAL ADMINISTRATION OF FMRFAMIDE PRODUCES ANTIPSYCHOTIC-LIKE EFFECTS IN RODENTS

Neuropeptide FMRFamide (Phe-Met-Arg-Phe-NH2,) was evaluated in animal models of psychosis. FMRFamide (0.5-100 mu g, i.c.v.) produced blockad e of conditioned avoidance response in rats and antagonized apomorphin e-induced climbing behaviour in mice. Similarly, FMRFamide at lower do ses (0.1-10 mu g, i.c.v.) inhibited 5-hydroxy-L-tryptophan (5-HTP)-ind uced head twitches in rats. These effects of the peptide were similar to haloperidol (1 mg/kg, i.p.). However, unlike haloperidol, FMRFamide per se did not induce any catalepsy in rats at the doses employed in the above paradigms. These results indicate antipsychotic-like activit y for the neuropeptide FMRFamide with possible involvement of the dopa minergic/5-HT2 systems.