Temple University School of Pharmacy, 3307 North Broad Street, Philadelphia, PA 19140, United States.
Drug Alcohol Depend. 2009 Dec 1;105(3):248-55. doi: 10.1016/j.drugalcdep.2009.07.002. Epub 2009 Aug 12.
Cannabinoid CB1 antagonists decrease self-administration of palatable food and several abused drugs in animals and modulate extinction of conditioned fear responses. Less is known, however, about whether and how CB1 antagonists might modulate the extinction of appetitive behavior. Therefore, this study examined the effects of the CB1 receptor antagonist rimonabant (SR141716) during extinction of responding maintained either by cocaine or by palatable foods (corn oil or Ensure), as well as responding elicited by stimulus cues that had been paired with the presentation of cocaine (i.e., cue-induced reinstatement) or a prime (presentation of cocaine or food). The effect of rimonabant on high rate responding in water-deprived mice trained to self-administer water was also examined. In mice self-administering cocaine, rimonabant attenuated cue-induced reinstatement of cocaine self-administration, the initial burst of responding during cocaine extinction and responding during spontaneous recovery. In mice self-administering corn oil, rimonabant decreased responding during extinction and also attenuated responding that had been reinstated by a priming presentation of corn oil. Moreover, mice treated with rimonabant required fewer daily sessions to reach criterion for extinction of cocaine-maintained responding than vehicle treated mice. Also, rimonabant had no effect on the rate of operant responding in mice trained to respond for water under an FR5 schedule of reinforcement. Taken together, these data suggest that in addition to attenuating the primary reinforcing effects of both palatable foods and drugs of abuse, CB1 receptor antagonism can attenuate context and cue reactivity during extinction learning and potentially enhance extinction learning in this way.
大麻素 CB1 拮抗剂可减少动物对美味食物和几种滥用药物的自我给药,并调节条件性恐惧反应的消退。然而,关于大麻素 CB1 拮抗剂是否以及如何调节食欲行为的消退知之甚少。因此,本研究检查了 CB1 受体拮抗剂利莫那班(SR141716)在可卡因或美味食物(玉米油或 Ensure)维持的反应消退期间以及与可卡因呈现配对的刺激线索引发的反应消退期间(即线索诱导的复吸)或启动(可卡因或食物呈现)期间的作用。还检查了利莫那班对接受水剥夺训练以自我给予水的小鼠的高反应率的影响。在自我给予可卡因的小鼠中,利莫那班减弱了可卡因自我给药的线索诱导复吸、可卡因消退期间的初始爆发反应和自发恢复期间的反应。在自我给予玉米油的小鼠中,利莫那班减少了消退期间的反应,并减弱了由玉米油的启动呈现引发的反应。此外,与接受载体治疗的小鼠相比,接受利莫那班治疗的小鼠在达到可卡因维持反应消退的标准所需的每日疗程更少。此外,利莫那班对接受强化方案为 FR5 的水操作反应的小鼠的操作性反应率没有影响。总之,这些数据表明,除了减弱美味食物和滥用药物的主要强化作用外,CB1 受体拮抗作用还可以减轻消退学习期间的上下文和线索反应,并以这种方式潜在地增强消退学习。