THE EFFECT OF NALTREXONE ON NICOTINE-INDUCED CONDITIONED PLACE PREFERENCE IN RATS

Nicotine is the central active ingredient in tobacco. The reinforcing effects of nicotine can be studied in animals through self-administration, conditioned place preference, and other approaches that enable researchers to assess nicotine cessation strategies. One strategy involves the use of opioid receptor antagonists. For instance, naloxone has been shown to reduce place preference for nicotine in rats, and other experimental opioid antagonists have also been shown to affect place preference for nicotine. The present study sought to extend these findings to the opioid antagonist naltrexone, which has long been FDA-approved for the treatment of opioid and alcohol addiction in humans. Using standard two-chamber shuttleboxes, we first sought to establish a place preference for nicotine in rats, and once this was achieved, we sought to block nicotine place preference with naltrexone. In the first experiment, subjects did not show a place preference for nicotine, but an alteration in the environmental stimuli used on the shuttleboxes led to a conditioned place preference for nicotine in the second experiment. In the third experiment, naltrexone did not block nicotine place preference. These results coincide with past findings that indicate a difficulty to establish a conditioned place preference for nicotine. This paper discusses these challenges and suggests other ways to evaluate a potential use for opioid receptor antagonists for treating nicotine addiction