Effect of cocaine on periadolescent rats with or without early maternal separation

Autor(es)

C.S. Planeta ^[1] ; M.T. Marin ^[2]

Afiliação do(s) autor(es)

^[1] Universidade Estadual Paulista. Faculdade de Ciências Farmacêuticas. Laboratório de Farmacologia - Brasil

^[2] Universidade Estadual Paulista. Faculdade de Ciências Farmacêuticas. Laboratório de Farmacologia - Brasil

• Tipo de documento: Artigo Científico
• Fonte: Brazilian Journal of Medical and Biological Research; v. 35, n. 11, p. 1367-1371, 2002-11-00.

Resumo

Cocaine-induced behavioral sensitization and weight loss were investigated in periadolescent Wistar rats kept with their mothers or subjected to repeated maternal separation. Litters allocated to the separation procedure were placed in a temperature-controlled (33ºC) chamber for 3 h per day from postnatal day 6 (P6) to P20. Non-handled rats were left undisturbed until weaning. Treatments were started on P30-31 and the test was performed on P36-37. Animals received injections of saline or cocaine (10 mg/kg, sc) twice daily for 5 days. On day 6 all animals received saline. On day 7 animals were challenged with 10 mg/kg cocaine and their locomotion was evaluated in activity cages. A third group received saline throughout the 7-day period. Body weights were recorded on P30-31 and P36-37. Two-way ANOVA on body weights showed a main effect of treatment group (F(1,35) = 10.446, P = 0.003; N = 10-12). Non-handled rats treated with cocaine for 5 days gained significantly less weight, while no significant effect was observed in maternally separated rats. Two-way ANOVA revealed a main effect of drug treatment on locomotor activity (F(2,32) = 15.209, P<0.001; N = 6-8), but not on rearing condition (F(1,32)<0.001, P = 0.998). Animals pretreated with cocaine showed a clear behavioral sensitization relative to the saline group. No difference in the magnitude of sensitization was found between separated and non-handled animals. Only the effect of cocaine on weight gain was significantly affected by repeated episodes of early maternal separation during the pre-weaning period. (AU)

• Processo FAPESP: 97/11010-2 - Exposição ao estresse durante o desenvolvimento: consequências sobre os efeitos comportamentais e moleculares da cocaína em ratos
• Beneficiário: Cleopatra da Silva Planeta
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores
• Processo FAPESP: 00/09319-0 - Efeito da separação materna na sensibilização comportamental induzida pela cocaína
• Beneficiário: Marcelo Tadeu Marin
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica