延长药物获取和戒断对恒河猴药物选择的调制:对作为成瘾驱动因素和药物开发靶点的负性强化的意义。
Modulation of drug choice by extended drug access and withdrawal in rhesus monkeys: Implications for negative reinforcement as a driver of addiction and target for medications development.
机构信息
Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
Department of Pharmacology and Toxicology, Virginia Commonwealth University, Richmond, VA 23298, USA.
出版信息
Pharmacol Biochem Behav. 2018 Jan;164:32-39. doi: 10.1016/j.pbb.2017.04.006. Epub 2017 Apr 22.
Chronic drug exposure is hypothesized to recruit negative reinforcement processes that increase the magnitude and alter the mechanisms of drug reinforcement. Candidate substrates of negative reinforcement include increased signaling via stress-related neurotransmitters such as corticotropin releasing factor (CRF, acting at CRF receptors) or dynorphin (acting at kappa opioid receptors) and/or decreased signaling via reward-related neurotransmitters such as dopamine. Determinants of drug reinforcement can be examined with choice procedures, in which subjects choose between a drug of interest (e.g. heroin or cocaine) and a non-drug alternative reinforcer (e.g. food). This review summarizes evidence collected from studies of drug choice in rhesus monkeys to address the negative reinforcement hypothesis. In monkeys choosing between heroin and food, chronic heroin exposure and subsequent withdrawal produces a robust increase in heroin choice. This withdrawal-associated increase in heroin choice is blocked by morphine and by other mu opioid agonists used to treat opioid use disorder (methadone, buprenorphine); however, withdrawal-associated increases in heroin choice are not reliably blocked by antagonists of CRF or kappa opioid receptors or by an indirect dopamine agonist. In monkeys choosing between cocaine and food, chronic cocaine exposure and withdrawal fail to increase cocaine choice or alter sensitivity of cocaine choice to treatment with candidate therapeutics including an indirect dopamine agonist and a kappa opioid receptor antagonist. These results support a role for negative reinforcement in self-administration of heroin but not cocaine. The constellation of neurobiological changes that constitutes the negative reinforcing stimulus in opioid-dependent rhesus monkeys remains to be determined.
慢性药物暴露被假设招募负强化过程,增加药物强化的幅度并改变其机制。负强化的候选底物包括应激相关神经递质(如促肾上腺皮质释放因子(CRF,作用于 CRF 受体)或强啡肽(作用于κ阿片受体))的信号传递增加,和/或奖励相关神经递质(如多巴胺)的信号传递减少。可以通过选择程序来检查药物强化的决定因素,在该程序中,受试者在感兴趣的药物(例如海洛因或可卡因)和非药物替代强化剂(例如食物)之间进行选择。这篇综述总结了从恒河猴药物选择研究中收集的证据,以解决负强化假说。在选择海洛因和食物的猴子中,慢性海洛因暴露和随后的戒断会导致海洛因选择的强烈增加。这种戒断相关的海洛因选择增加被吗啡和用于治疗阿片类药物使用障碍的其他μ阿片类激动剂(美沙酮、丁丙诺啡)阻断;然而,CRF 或κ阿片受体拮抗剂或间接多巴胺激动剂对戒断相关的海洛因选择增加没有可靠的阻断作用。在选择可卡因和食物的猴子中,慢性可卡因暴露和戒断不会增加可卡因的选择或改变候选治疗药物(包括间接多巴胺激动剂和κ阿片受体拮抗剂)对可卡因选择的敏感性。这些结果支持负强化在海洛因自我给药中的作用,但不是可卡因。在依赖阿片类药物的恒河猴中构成负强化刺激的神经生物学变化组合仍有待确定。