RESUMO
The effects of chronic ethanol administration were studied in rats receiving amygdaloid kindling. Daily ethanol administration 10 min prior to kindling stimulation delayed acquisition of kindling without affecting the electrical afterdischarge. For the lowest tested dose of ethanol (0.5 g/kg), this delay was restricted to kindling stages 1 and 2. For the higher doses of ethanol (1.0 and 1.5 g/kg) this delay became more severe and stages 3 and 4 were blocked. Ethanol produced a clear dose-related anticonvulsant effect upon kindled seizures. After repeated exposure to kindling stimulation and ethanol this anticonvulsant effect vanished. After a 15-day interval without stimulation or ethanol application kindled animals were insensitive to ethanol's anticonvulsant effect. In conclusion, it is suggested that the anticonvulsant effects of low ethanol doses are restricted to kindling stages 1 and 2 and that anticonvulsant effects of high ethanol doses are limited by tolerance and by the level of consolidation of the kindled seizure. Finally, we suggest that the anticonvulsant properties of ethanol are not due to its general depressant effect but to some rather specific action.
Assuntos
Tonsila do Cerebelo/fisiologia , Etanol/farmacologia , Excitação Neurológica , Convulsões/etiologia , Animais , Relação Dose-Resposta a Droga , Excitação Neurológica/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos , Tempo de Reação , Convulsões/fisiopatologia , Fatores de TempoRESUMO
1. The effect of acute ethanol on memory was studied in an eight-arm radial maze by interposing a 15-s or 1-h delay between the rat's fourth and fifth arm choices. 2. Ethanol (1.0 g/kg) was injected intraperitoneally 5 min prior to the first set of 4-arm choices, therefore being present since the acquisition of the trial-unique event. 3. The results showed 1) a decrease in choice accuracy only in the final 4 arm choices after the 1-h delay, and 2) that errors consisted of re-entries into arms chosen before the delay was imposed. The data further support the contention that ethanol impairs retention of working memory.
Assuntos
Etanol/efeitos adversos , Memória/efeitos dos fármacos , Comportamento Espacial , Análise e Desempenho de Tarefas , Animais , Masculino , Ratos , Ratos Endogâmicos , Tempo de Reação , Retenção Psicológica/efeitos dos fármacosRESUMO
1. The effect of acute ethanol on memory was studied in an eight-arm radial maze by interposing a 15-s or 1-h delay between the rat's fourth and fifth arma choices. 2. Ethanol (1.0g/Kg) was injected intraperitoneally 5 min prior to the firsrt set of 4-arm choices, therefore being presrnt since the acquisition of the trial-unique event. 3. The results showed 1) a decrease in choice accuracu only in the final 4 arm choices after the 1-h delay, and 2) that errors consisted of re-entries into arms chosen before the delay was imposed. The data further support the contention that ethanol impairs retention of working memory