Behavioural effects of quinpirole following withdrawal of chronic treatment with the CB1 agonist, HU-210, in rats.
The present study investigated spontaneous and quinpirole-induced motor responses of in rats, following withdrawal from chronic treatment with the potent cannabinoid agonist HU-210. Withdrawal from chronic HU-210 (20 microg/kg daily, 14 days) produced a decrease in spontaneous activity at 1 and 2 days and enhanced the hyperactivity induced by acute administration of the dopamine D2 agonist quinpirole (0.5 mg/kg) at 4 days after the end of HU-210 treatment. Administration of quinpirole on day 4 of withdrawal from chronic HU-210 enhanced stereotyped responses and induced jumping behaviour. These results suggest that withdrawal from chronic exposure to cannabinoid agonists could induce a time-dependent alteration in dopamine D2 psychomotor function, leading to a behavioural disorganization, comparable to acute psychotic episodes after continuous cannabinoids.
Moreno
M
M
Departamento de Psicobiologia, Facultad de Psicologia, Instituto Universitario de Drogodependencias, Universidad Complutense de Madrid, Spain. margamoreno75@yahoo.es
Lopez-Moreno
J A
JA
Rodríguez de Fonseca
F
F
Navarro
M
M
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D013759:Dronabinol / Q000031:analogs & derivatives* / Q000494:pharmacology; D008297:Male; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology; D019257:Quinpirole / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists* / Q000502:physiology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology; D013997:Time Factors
D018491:Dopamine Agonists; D043884:Receptor, Cannabinoid, CB1; D019257:Quinpirole; D013759:Dronabinol; C062018:HU 211