Learning Not to Be Impulsive: Disruption by Experience of Alcohol Withdrawal

Rationale: There is extensive evidence that alcoholism and impulsivity are related, but the direction of causality is unclear.

Objectives: The aim of the present investigation was to study the effects of chronic ethanol treatment and withdrawal in measures of attention and impulse control in the five-choice serial reaction time task (5CSRTT) in mice.

Materials And Methods: C57BL/6J mice were trained in the 5CSRTT and then tested in a variable inter-trial interval (vITI) session, which promotes the emergence of premature responses, a measure of poor inhibitory control. Following chronic ethanol treatment, mice were tested in additional vITI sessions-in experiment 1, at 1, 7 and 14 days post-withdrawal, and in experiment 2, at 14, 28, 42 and 56 days post-withdrawal.

Results: Control animals showed a reduction in premature responding with experience of the vITI schedule. Compared to controls, previous ethanol treatment did not affect attention or impulsivity on first experience of the vITI procedure. Ethanol-treated animals showed sustained increased premature responding over sessions. This effect of ethanol treatment was not apparent in experiment 2, in which first exposure to the vITI schedule was delayed for 2 weeks following ethanol treatment.

Conclusions: Chronic ethanol treatment impaired the ability to learn to modify behaviour in order to gain access to reinforcement more frequently. This effect was related to the time since withdrawal.