Delavari Fatemeh, Sheibani Vahid, Esmaeilpour Khadijeh, Esmaeili-Mahani Saeid, Nakhaee Nouzar
PhD Candidate, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
Professor, Neuroscience Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman, Iran.
Addict Health. 2016 Fall;8(4):261-269.
Disturbances in maternal care have been associated with increased risk for drug abuse later in life. However, there has been little investigation of the effects of maternal separation (MS), a model of early life stress, on nicotine dependence, specifically during adolescence. In the present study, we aimed to investigate the effect of MS on nicotine-conditioned place preference (CPP) in adolescent male rats. We also examined the impact of nicotine on spatial learning and memory impairments induced by MS.
Rat pups were exposed to daily MS for 15 (MS15) or 180 (MS180) minutes during the first 2 weeks of life or reared under normal animal facility rearing (AFR) conditions. In postnatal day (PND) 28-34, they were conditioned with nicotine [0.6 mg/kg, subcutaneously (SC)] or saline and tested for preference over a period of 6 conditioning trials. Morris water maze (MWM) testing was performed to assess spatial cognitive function.
The MS procedure used in our study failed to affect nicotine reward as measured by CPP in the adolescent male rats. Notably, significant spatial learning deficit was seen in the MS180 rats compared to those in the AFR and MS15 groups and nicotine administration modified the MS-induced learning defect in adolescent male rats.
In conclusion, although MS revealed no influence on the sensitivity to the nicotine's reinforcing effects in adolescent male rats, the simultaneous effect of MS on learning performance may be altered by nicotine intake.
母婴护理方面的紊乱与日后药物滥用风险增加有关。然而，作为一种早期生活应激模型，母婴分离（MS）对尼古丁依赖的影响，尤其是在青春期期间，鲜有研究。在本研究中，我们旨在探究MS对青春期雄性大鼠尼古丁条件性位置偏爱（CPP）的影响。我们还研究了尼古丁对MS诱导的空间学习和记忆障碍的影响。
在出生后的前2周，将幼鼠每天暴露于MS环境15（MS15）或180（MS180）分钟，或在正常动物饲养设施（AFR）条件下饲养。在出生后第28 - 34天，用尼古丁[0.6毫克/千克，皮下注射（SC）]或生理盐水对它们进行条件反射训练，并在6次条件反射试验期间测试其偏爱情况。进行莫里斯水迷宫（MWM）测试以评估空间认知功能。
我们研究中使用的MS程序未能影响青春期雄性大鼠通过CPP测量的尼古丁奖赏。值得注意的是，与AFR组和MS15组相比，MS180组大鼠出现了明显的空间学习缺陷，并且给予尼古丁改善了青春期雄性大鼠中MS诱导的学习缺陷。
总之，虽然MS对青春期雄性大鼠对尼古丁强化作用的敏感性没有影响，但MS对学习表现的同时影响可能会因尼古丁摄入而改变。
