Key Lab of Mental Health, Institute of Psychology, Chinese Academy of Sciences, 4A Datun Road, Chaoyang District, 100101 Beijing, PR China.
Neurosci Lett. 2010 Sep 20;482(1):12-6. doi: 10.1016/j.neulet.2010.06.074. Epub 2010 Jul 3.
Prenatal exposure to morphine can alter the capacities for learning and memory and the sensitivity to drugs of abuse in progeny. In the present study, we examined the effects of morphine during chick embryonic period of 5-8, 9-12, 13-16 and 17-20 on cognitive function and the sensitivities to morphine reward in the post-hatch chick, using the one-trial passive avoidance learning task and the conditioned place preference paradigm. It was observed that the injection of morphine (1mg/kg of egg weight) during E5-8, but not in other three periods, significantly impaired intermediate- and long-term memory in one-day-old chicks. On the other hand, the chicks prenatally exposed to morphine during E17-20 remarkably not only acquired but also maintained the conditioned place preference induced by morphine. The present results suggest that there are two time-windows during development, which in the chick are around E5-8 and E17-20, when prenatal morphine exposure is likely to confer maximal risks for vulnerabilities to breakdown of memory consolidation and to morphine-induced reward in day-old chicks respectively.
产前暴露于吗啡可改变后代的学习和记忆能力以及对滥用药物的敏感性。在本研究中，我们使用单次被动回避学习任务和条件性位置偏爱范式，研究了在鸡胚胎期 5-8 天、9-12 天、13-16 天和 17-20 天期间给予吗啡对孵化后雏鸡认知功能和对吗啡奖赏的敏感性的影响。结果表明，在 E5-8 期间注射吗啡（1mg/kg 卵重）显著损害了 1 日龄雏鸡的中、长期记忆，但在其他三个时期则没有显著影响。另一方面，在 E17-20 期间暴露于吗啡的雏鸡不仅明显获得了吗啡诱导的条件性位置偏爱，而且还能保持这种偏爱。本研究结果表明，在鸡的发育过程中有两个时间窗口，即 E5-8 和 E17-20 左右，在这两个时间窗口内，产前吗啡暴露可能分别使记忆巩固受损和吗啡诱导的奖赏的易感性达到最大。
