Phencyclidine-induced head-weaving observed in mice after ritanserin treatment.
Ritanserin (0.125, 0.25, 0.5, 1.0 and 2.0 mg/kg s.c.), a selective serotonin (5-HT2) receptor antagonist, produced a dose-dependent inhibition of the head-twitch response induced in mice by phencyclidine (PCP) and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT). In contrast, ritanserin, dose dependently increased PCP- and 5-MeODMT-induced head-weaving. There was a significant inverse relationship between head-twitch and head-weaving responses. Pretreatment with p-chlorophenylalanine (PCPA, 300 mg/kg i.p.), a serotonin synthesis inhibitor, attenuated the head-weaving induced by the combination of PCP (12.5 mg/kg i.p.) and ritanserin but PCPA did not alter the 5-MeODMT-induced head-weaving. These results indicate that PCP induces head-weaving by interacting with a 5-HT receptor (possibly of the 5-HT1 subtype) indirectly after 5-HT release and induces head-twitch by interacting with 5-HT2 receptors directly.
D000818:Animals; D010134:Fenclonine / Q000494:pharmacology; D006635:Histamine H2 Antagonists / Q000494:pharmacology*; D008297:Male; D008732:Methoxydimethyltryptamines / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D010622:Phencyclidine / Q000494:pharmacology*; D010869:Pindolol / Q000494:pharmacology; D010880:Piperidines / Q000494:pharmacology*; D016713:Ritanserin; D013239:Stereotyped Behavior / Q000187:drug effects*
D006635:Histamine H2 Antagonists; D008732:Methoxydimethyltryptamines; D010880:Piperidines; D016713:Ritanserin; D010869:Pindolol; D010622:Phencyclidine; D010134:Fenclonine