The nicotinic antagonist mecamylamine preferentially inhibits cocaine vs. food self-administration in rats

• Published in: Physiology & behavior 2000-12, Vol.71 (5), p.565-570
• Main Authors: Levin, Edward D., Mead, Tonya, Rezvani, Amir H., Rose, Jed E., Gallivan, Camille, Gross, Rita
• Format: Article
• Language: English
• Subjects: Animals; Behavioral psychophysiology; Biological and medical sciences; Cocaine; Cocaine - administration & dosage; Cocaine - pharmacology; Conditioning, Operant - drug effects; Dopamine Uptake Inhibitors - administration & dosage; Dopamine Uptake Inhibitors - pharmacology; Eating - drug effects; Female; Food; Fundamental and applied biological sciences. Psychology; Mecamylamine; Mecamylamine - pharmacology; Neurotransmission and behavior; Nicotinic Antagonists - pharmacology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Rats; Rats, Sprague-Dawley; Reinforcement (Psychology); Self Administration
• ISSN: 0031-9384; 1873-507X
• DOI: 10.1016/S0031-9384(00)00382-6

Nicotinic acetylcholine systems play important roles in addiction, and nicotinic receptor stimulation stimulates dopamine release while the nicotinic antagonist mecamylamine reduces it. Reid et al. [Neuropsychopharmacology 20 (1999) 297.] recently found in human cocaine addicts that mecamylamine reduced cue-elicited cocaine craving. The current study assessed the impact of mecamylamine on cocaine self-administration in rats. Female Sprague–Dawley rats ( N=7) were implanted with intravenous (iv) catheters and trained to lever press for cocaine (0.32 mg/kg/infusion FR-1 with a 60-s timeout) in 45-min sessions. After 2 weeks of training, the rats were injected with saline or mecamylamine (1, 2, or 4 mg/kg sc) 10 min before the session. They received the same dose for 1 week with 1 week of uninjected testing between doses. Mecamylamine, compared to saline, significantly ( P