These findings indicate that both the subjective effects of nicotine and the effects of nicotine on alcohol consumption differ markedly in men and women. The findings extend existing data on sex differences in the effects of either nicotine or cigarette smoking on alcohol consumption, and support the idea that the pharmacological effects of nicotine may differ in men and women.

These findings suggest that nicotinic cholinergic receptors are involved in mediating some of the stimulant-like effects of alcohol.

These results provide only limited support for the idea that nicotinic acetylcholine receptors are involved in the rewarding effects of alcohol.

Dopaminergic projections from the ventral tegmental area (VTA) to the nucleus accumbens (NAcc) mediate the behavioral and motivational effects of many drugs of abuse, including nicotine. Repeated intermittent administration of these drugs, a pattern often associated with initial drug exposure, sensitizes the reactivity of dopamine (DA) neurons in this pathway, enhances the locomotor behaviors the drugs emit, and promotes their pursuit and self-administration. Here we show that activation of nicotinic acetylcholine receptors (nAChRs) in the VTA, but not the NAcc, is essential for the induction of locomotor sensitization by nicotine. Repeated intermittent nicotine exposure (4 × 0.4 mg/kg, base, i.p., administered over 7 days), a regimen leading to long-lasting locomotor sensitization, also produced upregulation of nAChRs in the VTA, but not the NAcc, in the hours following the last exposure injection. Functional nAChR upregulation was observed selectively in DA but not GABA neurons in the VTA. These effects were followed by long-term potentiation of excitatory inputs to these cells and increased nicotine-evoked DA overflow in the NAcc. Withdrawal symptoms were not observed following this exposure regimen. Thus, intermittent activation and upregulation by nicotine of nAChRs in DA neurons in the VTA may contribute to the development of behavioral sensitization and increased liability for nicotine addiction.

No abstract