Li Xiaodan, Xiong Jian, Zhang Baojian, Zhangsun Dongting, Luo Sulan
Key Laboratory of Tropical Biological Resources of Ministry of Education, School of Pharmaceutical Sciences, Hainan University, Haikou, China.
Medical School, Guangxi University, Nanning, China.
Front Pharmacol. 2021 Dec 3;12:772990. doi: 10.3389/fphar.2021.772990. eCollection 2021.
Morphine, the main component of opium, is a commonly used analgesic in clinical practice, but its abuse potential limits its clinical application. Nicotinic acetylcholine receptors (nAChRs) in the mesolimbic circuitry play an important role in the rewarding effects of abused drugs. Previous studies have showed that α6β2* (* designated other subunits) nAChRs are mainly distributed in dopaminergic neurons in the midbrain area, which regulates the release of dopamine. So α6β2* nAChRs are regarded as a new target to treat drug abuse. α-Conotoxin TxIB was discovered in our lab, which is the most selective ligand to inhibit α6β2* nAChRs only. Antagonists of α6β2* nAChRs decreased nicotine, cocaine, and ethanol rewarding effects previously. However, their role in morphine addiction has not been reported so far. Thus, it is worth evaluating the effect of α-conotoxin TxIB on the morphine-induced conditioned place preference (CPP) and its behavioral changes in mice. Our results showed that TxIB inhibited expression and acquisition of morphine-induced CPP and did not produce a rewarding effect by itself. Moreover, repeated injections of TxIB have no effect on learning, memory, locomotor activity, and anxiety-like behavior. Therefore, blocking α6/α3β2β3 nAChRs inhibits the development of morphine-induced CPP. α-Conotoxin TxIB may be a potentially useful compound to mitigate the acquisition and/or retention of drug-context associations.
吗啡是鸦片的主要成分,是临床实践中常用的镇痛药,但其滥用潜力限制了其临床应用。中脑边缘回路中的烟碱型乙酰胆碱受体(nAChRs)在滥用药物的奖赏效应中起重要作用。先前的研究表明,α6β2*(表示其他亚基)nAChRs主要分布在中脑区域的多巴胺能神经元中,调节多巴胺的释放。因此,α6β2 nAChRs被视为治疗药物滥用的新靶点。α-芋螺毒素TxIB是我们实验室发现的,是仅抑制α6β2* nAChRs的最具选择性的配体。α6β2* nAChRs的拮抗剂先前已降低了尼古丁、可卡因和乙醇的奖赏效应。然而,它们在吗啡成瘾中的作用迄今尚未见报道。因此,评估α-芋螺毒素TxIB对吗啡诱导的条件性位置偏爱(CPP)及其在小鼠中的行为变化的影响是值得的。我们的结果表明,TxIB抑制吗啡诱导的CPP的表达和获得,并且其本身不会产生奖赏效应。此外,重复注射TxIB对学习、记忆、运动活动和焦虑样行为没有影响。因此,阻断α6/α3β2β3 nAChRs可抑制吗啡诱导的CPP的发展。α-芋螺毒素TxIB可能是一种潜在有用的化合物,可减轻药物与环境关联的获得和/或保留。