Molecular mechanisms of drug reinforcement and addiction.
Molecular mechanisms of drug reinforcement and addiction.
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DOI：
10.1146/annurev.ne.18.030195.002335
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发表时间：
1995
影响因子：
13.9
通讯作者：
D. Self;Eric J. Nestler
中科院分区：
文献类型：
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作者：
D. Self;Eric J. Nestler
药物强化是行为可塑性的一种形式，其中行为变化是由于急性暴露于强化药物而发生的。如果当反应与药物暴露暂时配对时寻求药物反应的概率增加，则药物被归类为强化剂。药物强化剂和药物寻求反应之间如此快速而强大的关联可能反映了药物直接调节先前存在的大脑强化系统的能力。这些预先存在的系统通常调节食物、性和社会互动等自然强化物产生的强化。在急性暴露后，大多数滥用药物都会起到积极强化剂的作用，大概是因为它们会产生积极的情感状态（例如欣快感）。长期接触强化药物会导致药物成瘾，其特征还在于寻求药物的行为增加。临床上，这种寻求药物行为（即渴望）的持续增加是药物成瘾的核心特征。然而，与非成瘾受试者的药物强化不同，即使药物不存在或戒断，成瘾受试者也会表现出寻求药物行为的持续增加。在某些情况下，药物可以起到负面强化剂的作用，因为它们可以缓解负面情绪状态（例如烦躁不安）。由于急性药物强化和成瘾状态的特征都是寻求药物行为的增加，因此常见
Drug reinforcement is a form of behavioral plasticity in which behavioral changes occur in response to acute exposure to a reinforcing drug. Drugs are classified as reinforcers if the probability of a drug-seeking response is in creased when the response is temporally paired with drug exposure. Such rapid and powerful associations between a drug reinforcer and a drug-seeking re sponse probably reflect the drug's ability to directly modulate preexisting brain-reinforcement systems. These preexisting systems normally mediate the reinforcement produced by natural reinforcers such as food, sex, and social interaction. Upon acute exposure most abused drugs function as positive rein forcers, presumably because they produce a positive affective state (e.g. eu phoria). Chronic exposure to reinforcing drugs can lead to drug addiction, which is also characterized by an increase in drug-seeking behavior. Clinically, this sustained increase in drug-seeking behavior (Le. craving) is a core feature of drug addiction. However, unlike drug reinforcement in nonaddicted subjects, addicted subjects exhibit a sustained increase in drug-seeking behavior even when the drug is absent or withdrawn. In some of these situations drugs can function as negative reinforcers in that they offer relief from a negative affec tive state (e.g. dysphoria). Since acute drug reinforcement and the addicted state are both characterized by an increase in drug-seeking behavior, common