Backward walking and circling: behavioural responses induced by drug treatments which cause simultaneous release of catecholamines and 5-hydroxytryptamine.
1 The roles of catecholamine and 5-hydroxytryptamine (5-HT) release in mediating backward walking and circling were studied in rats. 2 These behaviours occurred in animals given 15 mg/kg intraperitoneally of (+)-amphetamine (which predominantly releases catecholamines) or either p-chloroamphetamine or fenfluramine (which predominantly release 5-HT). They also occurred when smaller doses of (+)-amphetamine (5 mg/kg) and either p-chloroamphetamine (2--5 mg/kg) or fenfluramine (5 mg/kg) were given together. 3 Characteristic dopamine-dependent behaviours (rearing, licking, gnawing) resulting from (+)-amphetamine injection were greatly reduced by p-chloroamphetamine or fenfluramine. 4 Characteristic 5-HT-dependent behaviours (wet dog shake, hind limb abduction) resulting from injection of either p-chloroamphetamine or fenfluramine were unaffected by (+)-amphetamine. 5 Fragmentary backward walking and circling resulting from levallorphan injection (50 mg/kg s.c.) were decreased by (+)-amphetamine at low dosage. 6 Results in general strengthen previous evidence that backward walking and circling are mediated by simultaneous dopamine and 5-HT release. 7 The possible relevance of the above findings to hallucinogenic activity, amphetamine psychosis, schizophrenia and abnormal movements due to L-DOPA treatment is discussed.
D000662:Amphetamines / Q000494:pharmacology*; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D003913:Dextroamphetamine / Q000494:pharmacology*; D004347:Drug Interactions; D005277:Fenfluramine / Q000494:pharmacology*; D007977:Levallorphan / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D051381:Rats; D012701:Serotonin / Q000378:metabolism*; D010133:p-Chloroamphetamine / Q000494:pharmacology*
D000662:Amphetamines; D002395:Catecholamines; D005277:Fenfluramine; D012701:Serotonin; D007977:Levallorphan; D010133:p-Chloroamphetamine; D003913:Dextroamphetamine