Prior alcohol consumption does not impair go/no-go discrimination learning, but causes over-responding on go trials, in rats

• Published in: Behavioural brain research 2016-10, Vol.312, p.272-278
• Main Authors: Pickens, Charles L., Fisher, Hayley, Bright, Nicholas, Gallo, Mark, Ray, Madelyn H., Anji, Antje, Kumari, Meena
• Format: Article
• Language: English
• Subjects: Alcohol; Alcohol Drinking; Animals; Conditioning, Operant - drug effects; Discrimination learning; Discrimination Learning - drug effects; Ethanol - administration & dosage; Impulsivity; Inhibitory control; Male; Operant conditioning; Psychomotor Performance - drug effects; Rats; Rats, Long-Evans; Reinforcement (Psychology); Withdrawal
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2016.06.028

•Withdrawal from alcohol did not impair the ability to learn a go/no-go discrimination.•Withdrawal from alcohol led to over-responding to a reinforced response option that provided limited reinforcement.•Alcohol injections decreased voluntary consumption of alcohol. Prior alcohol use is associated with impaired response inhibition in humans, including in laboratory go/no-go discrimination tasks. In two experiments, we determined whether chronic intermittent access to alcohol would alter go/no-go discrimination learning. Rats received 4–6 weeks of chronic intermittent access to 20% alcohol (alone or accompanied by saline or 1.5g/kg alcohol injections) or water. Rats then began discrimination training 4–5days after the end of the alcohol access. Each lever was available for 40s with one lever intermittently reinforced (“active lever”) and the other lever non-reinforced (“inactive lever”). The rats given access to alcohol without concurrent alcohol injections drank ∼10g/kg/24-h on average during the last three weeks of alcohol access. The groups given alcohol injections (Alcohol+Injection groups) exhibited suppressed drinking, but the Alcohol+Injection groups exhibited higher blood alcohol spikes than all other alcohol groups (195 vs. 85–90mg/dl, respectively). We found no evidence for impaired go/no-go discrimination learning in either experiment. However, the alcohol access groups with moderate-to-high average alcohol consumption (>3g/kg/24-h) exhibited over-responding to the active lever compared to the water-only groups. One group given alcohol injections (Alcohol+Injection group) that exhibited very low voluntary drinking (