Varenicline is one of the top medications used for smoking cessation and is often prescribed before termination of nicotine use. The effect of this combined nicotine and varenicline use on the reward system and motivation for primary reinforcement is underexplored. The goal of this study was to assess the effects of nicotine and varenicline on motivation for a food reinforcer. In Experiment 1, we first assessed the responding for sucrose after pretreatment with nicotine (0, 0.1, or 0.4 mg/kg) and varenicline (0.0, 0.1, 1.0 mg/kg) using a behavioral economics approach. The responding for sucrose was then assessed using a progressive ratio schedule of reinforcement after pretreatment with all possible combinations of nicotine and varenicline doses. In Experiment 2, rats were assessed for the consumption of sucrose in home cages after pretreatment with nicotine and varenicline. We found that a) nicotine decreased economic demand for sucrose, b) varenicline rescued nicotine-induced reduction in economic demand for sucrose, and c) history of varenicline treatment predicted responding for sucrose on a progressive ratio schedule of reinforcement where rats with a history of varenicline treatment responded significantly lower for sucrose across nicotine doses than rats that had not beeng exposed to varenicline. The results of Experiment 2 largely confirmed that nicotine decreases motivation for sucrose using a passive consumption protocol and that varenicline rescues this effect. Overall, these findings suggest that varenicline interacts with the effects of nicotine by restoring nicotine-induced reduction in motivation for appetitive rewards.

Varenicline 是用于戒烟的顶级药物之一，通常在终止尼古丁使用之前开处方。这种尼古丁和伐尼克兰联合使用对奖励系统和初级强化动机的影响尚未得到充分探索。本研究的目的是评估尼古丁和伐尼克兰对食物强化剂动机的影响。在实验 1 中，我们首先使用行为经济学方法评估了用尼古丁（0、0.1 或 0.4 mg/kg）和伐尼克兰（0.0、0.1、1.0 mg/kg）预处理后对蔗糖的反应。然后在用尼古丁和伐尼克兰剂量的所有可能组合预处理后，使用渐进比例的强化方案评估对蔗糖的反应。在实验 2 中，在用尼古丁和伐尼克兰预处理后，评估大鼠在家笼中的蔗糖消耗量。我们发现 a) 尼古丁减少了对蔗糖的经济需求，b) 伐尼克兰挽救了尼古丁引起的对蔗糖的经济需求减少，以及 c) 伐尼克兰治疗的历史预测了对蔗糖的反应，其中大鼠有伐尼克兰治疗对尼古丁剂量中蔗糖的反应明显低于未接触伐尼克兰的大鼠。实验 2 的结果在很大程度上证实了尼古丁使用被动消费协议降低了对蔗糖的动力，而伐尼克兰挽救了这种效应。全面的，