Central Institute of Mental Health (ZI), Department of Psychopharmacology, Mannheim, Germany.
Behav Brain Res. 2010 Apr 2;208(2):466-72. doi: 10.1016/j.bbr.2009.12.013. Epub 2009 Dec 24.
In the present study dose-dependent effects of the opioid receptor antagonist naloxone were investigated on the rewarding effects of sweetened condensed milk (SCM) in four behavioral paradigms addressing hedonic, consummatory as well as motivational aspects of a reward: odour-conditioned pleasure attenuation of the acoustic startle response (PAS), conditioned place preference (CPP), voluntary consumption in a limited access paradigm, as well as break point determination in a progressive ratio (PR) task. A dose-dependent reduction in reward-related behavior was observed in all paradigms, with exception of the break point in the PR task, which was not affected by naloxone at all. CPP for SCM was only affected by the highest dose of naloxone. The present results indicate that naloxone is more effective in suppressing the hedonic than motivational aspects of reward, further supporting the involvement of the endogenous opioid system in the mediation of hedonic properties of food reward.
在本研究中，我们研究了阿片受体拮抗剂纳洛酮对甜味炼乳（SCM）奖赏效应的剂量依赖性影响，使用了四个行为范式来研究奖赏的愉悦、消费和动机方面：气味条件性快感衰减的听觉惊跳反应（PAS）、条件性位置偏好（CPP）、有限接入范式中的自愿消费，以及在渐进比率（PR）任务中确定的断点。在所有范式中，观察到奖赏相关行为呈剂量依赖性降低，除了 PR 任务中的断点，纳洛酮对其完全没有影响。SCM 的 CPP 仅受纳洛酮最高剂量的影响。本研究结果表明，纳洛酮在抑制愉悦方面比在抑制动机方面更有效，这进一步支持了内源性阿片系统在调节食物奖赏的愉悦特性中的作用。
