Differential Modulation by the Stress Axis of Ethanol Withdrawal Seizure Expression in WSP and WSR Mice

Abstract

Withdrawal from both acute and chronic ethanol (EtOH) exposure is associated with increased neural excitability and increased activity of the hypothalamic-pituitary-adrenal axis. There is some evidence that glucocorticoids are necessary for EtOH withdrawal seizure expression. Lines of mice that were selected for severe (WSP) and minimal (WSR) EtOH withdrawal (as estimated from handling-induced convulsion scores) have been shown to differ in their stress response following an acute dose of EtOH. In this study we provide evidence that these lines of mice also differ in their sensitivity to the excitatory effects of glucocorticoids. EtOH withdrawal seizures of WSP mice were significantly increased by chronic and acute corticosterone treatment, whereas those of the WSR mice were unaffected. Neural excitability was decreased in the WSP mice when aminoglutethimide, a glucocorticoid synthesis blocker, was administered. Thus, it appears that genetic differences in EtOH withdrawal seizure severity may be due, in part, to differences in sensitivity to the excitatory effects of glucocorticoids.