Mecamylamine increases nicotine preference and attenuates nicotine discrimination

Area of Science:

• Pharmacology
• Neuroscience
• Tobacco Research

Background:

• Nicotinic acetylcholine receptors (nAChRs) are key targets for nicotine's effects.
• Understanding how nAChR blockade influences subjective responses to cigarette smoke is crucial for smoking cessation strategies.

Purpose of the Study:

• To investigate the effects of mecamylamine, a nicotinic receptor blocker, on subjective evaluations of cigarette smoke.
• To determine how mecamylamine influences nicotine dose preference and cigarette craving.

Main Methods:

• Eight subjects received varying doses of mecamylamine (0-20 mg).
• Subjects evaluated high and low nicotine cigarette smoke under different mecamylamine conditions.
• Subjects adjusted nicotine levels to determine dose preference with mecamylamine administration.

Main Results:

• Mecamylamine dose-dependently reduced the perceived strength and harshness of high-nicotine smoke, with minimal effect on low-nicotine smoke.
• Low mecamylamine doses decreased reported desire for cigarettes and attenuated smoking-induced desire reduction.
• Higher mecamylamine doses led to increased self-administered nicotine, yet smoking still reduced desire less than placebo.

Conclusions:

• Nicotinic receptor blockade significantly alters the subjective experience of cigarette smoking.
• Mecamylamine's effects on smoke perception and craving suggest a role for nAChRs in nicotine dependence.
• While mecamylamine can reduce craving, compensatory increases in nicotine intake highlight the complexity of modulating smoking behavior.