Effects of age and isolation on the evolution of catalepsy during chronic haloperidol treatment.
Sixteen young (5 months) and 16 old (20-24 months) male Wistar rats, housed together or in individual cages were observed for cataleptic behavior 10, 20 and 30 days after the beginning of chronic haloperidol treatment (1.0 mg/kg, twice daily, for 30 days). Catalepsy was measured by the bar test. Age increased the duration of haloperidol-induced catalepsy of isolated and group-housed rats in the three observation sessions (old-isolated = 7.4 +/- 0.2; old-group housed = 7.5 +/- 0.1; young-isolated = 6.3 +/- 0.2; young-group housed = 6.8 +/- 0.2 In seconds in session 1, for example). Conversely, isolation did not modify the sensitivity to the cataleptic effect of haloperidol. Even more important, no differences in duration of haloperidol-induced catalepsy were observed among the three sessions for each group. The results indicate that under the experimental conditions employed the animals did not develop tolerance nor sensitization to haloperidol-induced catalepsy. In addition, neither age nor isolation modified the absence of effects of repeated haloperidol treatment on the catalepsy behavior of rats.
Frussa-Filho
R
R
Departamento de Farmacologia, Escola Paulista de Medicina, São Paulo, Brasil.
Otoboni
J R
JR
Uema
F T
FT
Palermo-Neto
J
J
D000375:Aging / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D002375:Catalepsy / Q000139:chemically induced* / Q000503:physiopathology; D004361:Drug Tolerance; D006220:Haloperidol / Q000494:pharmacology*; D006799:Housing, Animal; D008297:Male; D051381:Rats; D012934:Social Isolation; D013997:Time Factors
D006220:Haloperidol