title: Induction of purposeless chewing behaviour in rats by 5-HT agonist drugs.
abstract: The 5-HT agonist m-chlorophenylpiperazine (m-CPP; 1-16 mg/kg i.p. or s.c.), trifluoromethylphenylpiperazine (TFMPP; 2-16 mg/kg i.p.) and quipazine (2.5-20 mg/kg i.p.) increased purposeless chewing behaviour in rats. However, 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT; 0.025-4 mg/kg s.c.) and 5-methoxy-N,N-dimethyltryptamine (5-MeODMT; 0.25-8 mg/kg s.c.) were without effect on chewing behaviour. Chewing behaviour induced by m-CPP (6 mg/kg s.c.) was antagonised by pretreatment with the 5-HT antagonists methiothepin and mianserin, but not by ketanserin or spiperone, or ICS 205-930. m-CPP (6 mg/kg s.c.)-induced chewing behaviour was also antagonised by pretreatment with (-)-propranolol (20 mg/kg). Pretreatment with the anticholinergic drugs benzhexol (2.5 mg/kg), and scopolamine (1 mg/kg) antagonised m-CPP (6 mg/kg s.c.)-induced chewing behaviour, but methylscopolamine (1 mg/kg) had no effect. These data support the role of 5-HT receptors in the mediation of purposeless chewing behaviour and suggest an interaction between brain 5-HT and acetylcholine systems.
authors.affiliation: MRC Movement Disorders Research Group, University Department of Neurology, London, U.K.
authors.forename: B R
authors.initials: BR
authors.lastname: Stewart
authors.forename: P
authors.initials: P
authors.lastname: Jenner
authors.forename: C D
authors.initials: CD
authors.lastname: Marsden
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D008297:Male; D008719:Methiothepin / Q000494:pharmacology; D008732:Methoxydimethyltryptamines / Q000494:pharmacology; D008803:Mianserin / Q000494:pharmacology; D010276:Parasympatholytics / Q000494:pharmacology; D010879:Piperazines / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011814:Quipazine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology*; D013134:Spiperone / Q000494:pharmacology; D013764:Tetrahydronaphthalenes / Q000494:pharmacology
chemical_list: D008732:Methoxydimethyltryptamines; D010276:Parasympatholytics; D010879:Piperazines; D011985:Receptors, Serotonin; D013764:Tetrahydronaphthalenes; D008803:Mianserin; D011814:Quipazine; D013134:Spiperone; D008719:Methiothepin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D011433:Propranolol; C015068:1-(3-chlorophenyl)piperazine