Nicotine enhances responding with conditioned reinforcement
Nicotine enhances responding with conditioned reinforcement
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DOI：
10.1007/s00213-003-1575-y
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发表时间：
2004-01-01
影响因子：
3.4
通讯作者：
Taylor, JR
中科院分区：
文献类型：
--
作者：
Olausson, P;Jentsch, JD;Taylor, JR
理由。中脑边缘多巴胺系统与滥用药物的初级强化特性以及由精神兴奋剂药物产生的条件强化的增强反应有关。尽管临床观察表明尼古丁自我给药（即吸烟）强烈依赖于条件强化（即线索支持吸烟行为），但对尼古丁是否直接影响动机过程知之甚少。Objective.在这些实验中，我们研究了急性尼古丁是否会影响条件强化的反应，以及用烟碱乙酰胆碱受体（nAChR）拮抗剂美加明预处理会在多大程度上改变任何尼古丁诱导的行为效应。方法.在受试者已经被训练将初始中性刺激与水奖励相关联之后，他们接受急性尼古丁（43.25 -350 μ g/kg SC;约5分钟）或盐水注射，并测试条件强化范例的新反应的获得。在单独的实验中，还检查了单独用烟碱乙酰胆碱受体拮抗剂美加明（300或1000 μ g/kg SC;~ 20分钟）或与烟碱（350 μ g/kg SC;~ 5分钟）组合预处理对条件强化的影响。结果急性尼古丁注射产生了选择性增强的反应与条件强化（即在CR杠杆），而不产生非选择性增加整体响应。尼古丁（350 μ g/kg SC;约5分钟）的作用被美加明（300 μ g/kg）选择性阻断。结论.这些发现表明，急性暴露于尼古丁增强了条件反射者对行为的控制，表明尼古丁可能会增强动机过程。
Rationale. The mesolimbic dopamine system has been implicated in the primary reinforcing properties of drugs of abuse as well as in enhanced responding with conditioned reinforcement produced by psychomotor stimulant drugs. Despite clinical observations that nicotine self-administration (i.e. smoking) depends strongly upon conditioned reinforcement (i.e. cues support smoking behavior), little is known about whether nicotine directly affects motivational processes. Objective. In these experiments, we investigated whether acute nicotine would influence responding with conditioned reinforcement and the degree to which pretreatment with the nicotinic acetylcholine receptor (nAChR) antagonist mecamylamine would modify any nicotine-induced behavioral effects. Methods. After subjects had been trained to associate an initially neutral stimulus with water reward, they received acute nicotine (43,25-350 mug/kg SC; -5 min) or saline injections and were tested on the acquisition of a new response for conditioned reinforcement paradigm. In separate experiments, the effect of pretreatment with the nicotinic acetylcholine receptor antagonist mecamylamine (300 or 1000 mug/kg SC; -20 min) alone, or in combination with nicotine (350 mug/kg SC; -5 min), on conditioned reinforcement was also examined. Results. Acute nicotine injection produced a selective enhancement of responding with conditioned reinforcement (i.e. on the CR lever), without producing non-selective increases in overall responding. The effect of nicotine (350 mug/kg SC; -5 min) was selectively blocked by mecamylamine (300 mug/kg). Conclusions. These findings demonstrate that acute exposure to nicotine augments the control over behavior by a conditioned reinforcer, suggesting that nicotine may enhance motivational processes.