Nicotine increases alcohol self-administration and reinstates alcohol seeking in rats

• DOI: 10.1007/s00213-002-1330-9
• Publication Date: 2003-10-27T18:45:19Z
• Authors: A. D. Lê; A. Wang; S. Harding; W. Juzytsch; Y. Shaham
• Keywords: Male; Nicotine; Alcohol Drinking; Dose-Response Relationship, Drug; Ethanol; Self Administration; Rats; Behavior, Addictive; 03 medical and health sciences; 0302 clinical medicine; Reaction Time; Secondary Prevention; Animals; Rats, Long-Evans

Alcohol and tobacco are often co-abused in humans and previous studies found that nicotine increases alcohol consumption in rats. Here, we studied whether nicotine would reinstate alcohol-taking behavior in drug-free rats and whether this effect would be enhanced by prior exposure to nicotine during alcohol self-administration training.Rats were trained to press a lever for alcohol (12% w/v, 1 h/day), and following stable alcohol intake groups of rats ( n=11-12) were given daily vehicle or nicotine (0.2, 0.4 or 0.8 mg/kg, SC) injections just prior to the self-administration sessions for 10 days. Rats were then given 6 days of alcohol self-administration in the absence of nicotine and an additional 5-10 drug-free days during which lever presses were not reinforced (extinction). Subsequently, rats were tested for reinstatement of alcohol seeking following exposure to priming injections of vehicle or nicotine (0.4 mg/kg, SC).Nicotine increased alcohol self-administration in a dose- and time-dependent manner over the 10-day period. Nicotine also reinstated alcohol seeking after extinction of the alcohol-reinforced behavior, and this effect was strongly enhanced by prior nicotine exposure.The present data extend previous studies on the effect of nicotine on alcohol self-administration, and further indicate that nicotine is an effective stimulus for reinstatement of alcohol seeking during drug-free periods.