Barrett Scott T, Geary Trevor N, Steiner Amy N, Bevins Rick A
Department of Psychology, University of Nebraska, Lincoln, Nebraska, USA.
Behav Pharmacol. 2018 Sep;29(6):493-502. doi: 10.1097/FBP.0000000000000404.
Reinforcement value enhancement by nicotine of non-nicotine rewards is believed to partially motivate smoking behavior. Recently, we showed that the value-enhancing effects of nicotine are well characterized by reinforcer demand models and that the value-enhancing effects of the smoking-cessation aid bupropion (Zyban) are distinct from those of nicotine and differ between the sexes. The present study evaluated potential sex differences in the enhancement effects of nicotine and varenicline (Chantix) using a reinforcer demand methodology. The role of α4β2* and α7 nicotinic acetylcholine receptors (nAChRs) in the enhancing effects of nicotine and varenicline is also evaluated. Male and female rats (n=12/sex) were trained to lever press maintained by sensory reinforcement by visual stimulus (VS) presentations. Changes in the VS value following nicotine and varenicline administration were assessed using an established reinforcer demand approach. Subsequently, the effects of antagonism of α4β2* and α7 nAChRs on varenicline and nicotine-induced enhancement active lever-pressing were assessed using a progressive ratio schedule. Nicotine and varenicline enhanced VS demand equivalently between the sexes as evaluated by reinforcer demand. However, α4β2* receptor antagonism attenuated value enhancement by nicotine and varenicline in females, but only of nicotine in males.
尼古丁对非尼古丁奖赏的强化值增强作用被认为是吸烟行为的部分动机。最近，我们发现尼古丁的强化值增强效应可以通过强化物需求模型很好地描述，并且戒烟辅助药物安非他酮（畅沛）的强化值增强效应与尼古丁不同，且存在性别差异。本研究使用强化物需求方法评估了尼古丁和伐尼克兰（畅沛）强化效应中的潜在性别差异。同时也评估了α4β2和α7烟碱型乙酰胆碱受体（nAChRs）在尼古丁和伐尼克兰强化效应中的作用。雄性和雌性大鼠（每组12只）接受训练，通过视觉刺激（VS）呈现来维持杠杆按压行为。使用既定的强化物需求方法评估尼古丁和伐尼克兰给药后VS值的变化。随后，使用累进比率程序评估α4β2和α7 nAChRs拮抗剂对伐尼克兰和尼古丁诱导的主动杠杆按压增强作用的影响。根据强化物需求评估，尼古丁和伐尼克兰在两性中同等程度地增强了VS需求。然而，α4β2*受体拮抗剂减弱了尼古丁和伐尼克兰对雌性的强化值增强作用，但仅减弱了雄性中尼古丁的强化值增强作用。
