Diergaarde Leontien, Pattij Tommy, Nawijn Laura, Schoffelmeer Anton N M, De Vries Taco J
Department of Anatomy and Neurosciences, Vrije Universiteit Medical Center, Amsterdam, The Netherlands.
Behav Neurosci. 2009 Aug;123(4):794-803. doi: 10.1037/a0016504.
Poor impulse control has been associated with compulsive drug seeking and an enhanced risk of relapse, suggesting that impulsivity is causally related to addiction proneness and relapse vulnerability. However, whether this association is specific to drugs of abuse or whether heightened impulsivity relates to a general increase in sensitivity to rewards and reward-associated stimuli is unknown. To address this issue, the authors selected rats on the basis of individual differences in impulsive action in the 5-choice serial reaction time task, after which they were subjected to an operant sucrose self-administration paradigm. High-impulsive rats displayed a progressive increase in responding on the active hole (including responses emitted during the time-out period) in comparison with low-impulsive rats, which reflects escalation of sucrose-seeking behavior. Once sucrose and sucrose-associated stimuli were omitted (extinction training), nose-poke responding ceased rapidly, an effect that was independent of impulsivity level. In contrast, on reintroduction of sucrose-associated stimuli, sucrose seeking was successfully reinstated in high-impulsive but not in low-impulsive rats. Collectively, the results suggest that impaired response inhibition is associated with enhanced responsiveness to reward-associated stimuli. As such, elevated impulsivity might constitute a risk factor for the initiation and maintenance of addictive behaviors.
冲动控制能力差与强迫性觅药行为以及复发风险增加有关，这表明冲动性与成瘾倾向和复发易感性存在因果关系。然而，这种关联是否特定于滥用药物，或者冲动性增强是否与对奖励及奖励相关刺激的敏感性普遍增加有关，目前尚不清楚。为了解决这个问题，作者根据大鼠在5选串行反应时任务中的冲动行为个体差异进行挑选，然后让它们接受操作性蔗糖自我给药范式。与低冲动性大鼠相比，高冲动性大鼠在活动孔上的反应逐渐增加（包括在超时期间发出的反应），这反映了蔗糖觅求行为的升级。一旦省略蔗糖和蔗糖相关刺激（消退训练），鼻触反应迅速停止，这一效应与冲动性水平无关。相反，重新引入蔗糖相关刺激后，高冲动性大鼠成功恢复了蔗糖觅求行为，而低冲动性大鼠则没有。总体而言，结果表明反应抑制受损与对奖励相关刺激的反应增强有关。因此，冲动性升高可能是成瘾行为起始和维持的一个风险因素。
