Natural rewards and abused drugs affect the function of the common brain's reward system. Interaction between social and drug rewards can change the vulnerability to development of drug addiction. Here, we investigate the effects of sexual experience and sex deprivation on the acquisition, maintenance, and drug prime-induced reinstatement of morphine-seeking behavior in male mice using conditioned place preference (CPP). CPP induced with morphine (3, 5, 7 mg/kg, s.c. for 3 days) lasted for 10 days after cessation of morphine treatment and priming dose of morphine (2 mg/kg, s.c.) reinstated the extinguished CPP. In the post-test phase, sexually experienced animals showed a lower preference for morphine compared to sex-deprived males. In the extinction phase, sex deprivation shortened maintenance time compared to control animals. The preference for morphine in sexually experienced animals did not diminish by the seventeenth extinction day. In both groups, the priming injection of morphine after the extinction period could reinstate the extinguished morphine-induced CPP. Together, these data showed the interaction between sex and drug reward and that sexual behavior -a natural rewarding stimulus- can prolong, whereas sex deprivation can block the maintenance of morphine-seeking behaviors. Sexual experience may induce functional and morphological alterations in brain reward areas particularly the mesolimbic system similar to repeated exposure to abused drugs which can affect morphine-seeking behaviors.

自然奖励和滥用药物会影响普通大脑奖励系统的功能。社会和药物奖励之间的相互作用可以改变吸毒成瘾发展的脆弱性。在这里，我们使用条件性位置偏好 (CPP) 研究性经验和性剥夺对雄性小鼠吗啡寻求行为的获得、维持和药物诱导恢复的影响。吗啡诱导的 CPP（3、5、7 mg/kg，皮下 3 天）在吗啡治疗停止后持续 10 天，吗啡的初始剂量（2 mg/kg，皮下）恢复了熄灭的 CPP。在测试后阶段，与性剥夺的雄性相比，有性经验的动物对吗啡的偏好较低。在灭绝阶段，与对照动物相比，性剥夺缩短了维持时间。到第 17 个灭绝日，性经验丰富的动物对吗啡的偏好并未减弱。在两组中，消退期后的吗啡预注射可以恢复消退的吗啡诱导的 CPP。总之，这些数据显示了性和药物奖励之间的相互作用，并且性行为 - 一种自然的奖励刺激 - 可以延长，而性剥夺可以阻止吗啡寻求行为的维持。性经历可能会导致大脑奖励区域的功能和形态学改变，特别是中脑边缘系统，类似于反复接触可能影响吗啡寻求行为的滥用药物。消退期后注射吗啡可使消退的吗啡引起的CPP恢复。总之，这些数据显示了性和药物奖励之间的相互作用，并且性行为 - 一种自然的奖励刺激 - 可以延长，而性剥夺可以阻止吗啡寻求行为的维持。性经历可能会导致大脑奖励区域的功能和形态学改变，特别是中脑边缘系统，类似于反复接触可能影响吗啡寻求行为的滥用药物。消退期后注射吗啡可使消退的吗啡引起的CPP恢复。总之，这些数据显示了性和药物奖励之间的相互作用，并且性行为 - 一种自然的奖励刺激 - 可以延长，而性剥夺可以阻止吗啡寻求行为的维持。性经历可能会导致大脑奖励区域的功能和形态学改变，特别是中脑边缘系统，类似于反复接触可能影响吗啡寻求行为的滥用药物。