Bowles Center for Alcohol Studies, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
Department of Psychology, University of Nebraska at Lincoln, Lincoln, NE 68588, USA.
Pharmacol Biochem Behav. 2019 Apr;179:1-8. doi: 10.1016/j.pbb.2019.01.005. Epub 2019 Jan 19.
Smoking constitutes a significant public health risk. Alcohol and methamphetamine use disorders are also highly co-morbid with smoking, further increasing negative health outcomes. An important question in determining the underlying neurobiology of nicotine poly-drug use is understanding whether having a positive history with nicotine effects alters later drug-taking behavior.
The current experiments sought to elucidate whether having an appetitive nicotine conditioning history would affect later alcohol or methamphetamine self-administration. Adult male and female Long-Evans rats were first trained on a discriminated goal-tracking task in which the interoceptive effects of nicotine predicted sucrose reinforcement. As a control, pseudo-conditioned groups were included that had equated nicotine and sucrose experience. Rats were then shifted to either alcohol self-administration or methamphetamine self-administration.
Nicotine conditioning history had no effect on acquisition or maintenance of alcohol self-administration in males or females. In contrast, an appetitive nicotine conditioning history decreased methamphetamine self-administration in female rats, but not males.
In female, but not male, rats, an appetitive conditioning history with nicotine decreases methamphetamine, but not alcohol, self-administration. This dissociation suggests that the effects may be due to a specific increase in the reinforcing value of methamphetamine. This may have implications for better understanding the progression of drug use from nicotine to methamphetamine.
吸烟对公众健康构成重大风险。酒精和冰毒使用障碍也与吸烟高度共病，进一步增加了负面健康后果。在确定尼古丁多药物使用的潜在神经生物学基础时，一个重要问题是了解是否有吸烟的积极历史是否会改变以后的药物使用行为。
目前的实验旨在阐明是否有食欲性尼古丁条件作用史会影响以后的酒精或冰毒自我给药。成年雄性和雌性长耳大仓鼠首先在辨别性目标跟踪任务中接受训练，其中尼古丁的内感受作用预测蔗糖强化。作为对照，包括假条件组，它们具有相等的尼古丁和蔗糖经验。然后，大鼠被转移到酒精自我给药或冰毒自我给药。
尼古丁条件作用史对雄性或雌性的酒精自我给药的获得或维持没有影响。相比之下，食欲性尼古丁条件作用史减少了雌性大鼠的冰毒自我给药，但对雄性大鼠没有影响。
在雌性，但不是雄性大鼠中，食欲性尼古丁条件作用史减少了冰毒，但不减少酒精的自我给药。这种分离表明，这种作用可能是由于冰毒的强化价值的特定增加。这可能对更好地理解从尼古丁到冰毒的药物使用进展具有重要意义。
