Neuroleptics attenuate stereotyped behavior induced by beta-phenylethylamine in rats

β-phenylethylamine (PEA), a sympathomimetic amine, has been detected in a number of mammalian tissues (Wyatt et al., 1977), but its function is unknown. It is structurally similar to amphetamine; the only difference being the absence of a methyl group on the α-carbon of the side chain. PEA is preferentially degraded by the type B (Yang and Neff, 1973) monoamine oxidase (MAO) which is deficient in the platelets of some chronic schizophrenics (Wyatt and Murphy, 1976). PEA, like amphetamine, produces stereotyped behavior and hyperactivity in rats (Randrup and Munkvad, 1966; Sabelli et al., 1975); moreover, there are progressive increases in these behaviors with increasing dosages of both PEA and the monoamine oxidase inhibitor (MAOI), pargyline (Moja et al., 1976). In this paper we report modification of PEA-induced stereotyped behavior (in pargyline-pretreated rats) by neuroleptic drugs. Pargyline, when given in the doses used here, preferentially inhibits the B form of MAO (Fuentes and Neff, 1975).