Heyser C J, Miller J S, Spear N E, Spear L P
Department of Psychology, State University of New York, Binghamton 13902.
Neurotoxicol Teratol. 1992 Jan-Feb;14(1):57-64. doi: 10.1016/0892-0362(92)90029-a.
Cocaine-induced conditioned place preference (CPP) was tested in adult offspring of Sprague-Dawley dams that had been injected subcutaneously with 40 mg/kg/3cc cocaine HCl (C40) daily from gestational days 8-20, pair-fed (PF) dams injected with saline, and nontreated control (LC) dams. C40 and PF dams gained significantly less weight than LC dams, although offspring body weights did not differ among the three prenatal treatment groups at birth or in adulthood. Significant place conditioning was obtained in LC and PF offspring when either 2.0 or 5.0 mg/kg of cocaine was paired with the designated place. In contrast, C40 offspring did not exhibit place conditioning at either training dose. Yet, all animals exposed to 5 mg/kg of cocaine during conditioning exhibited less activity during the test (when no cocaine was given) than controls given unpaired exposures to the apparatus and cocaine and C40 offspring did not differ from LC and PF offspring in this respect. Therefore, despite their lack of a conditioned place preference for cocaine, rats that had been exposed gestationally to cocaine nevertheless revealed an effect of cocaine during conditioning in one aspect of their test behavior. Possible explanations for the lack of cocaine-induced place preference in these animals include a learning deficit or a change in cocaine's effectiveness as a reward.
在成年后代中测试了可卡因诱导的条件性位置偏爱（CPP），这些后代的母鼠为斯普拉格-道利大鼠，从妊娠第8天至20天每天皮下注射40mg/kg/3cc盐酸可卡因（C40），配对喂饲（PF）的母鼠注射生理盐水，以及未处理的对照（LC）母鼠。C40和PF母鼠的体重增加显著低于LC母鼠，尽管三个产前处理组的后代在出生时或成年时体重并无差异。当2.0或5.0mg/kg的可卡因与指定位置配对时，LC和PF后代出现了显著的位置条件反射。相比之下，C40后代在任何一个训练剂量下均未表现出位置条件反射。然而，在条件反射期间接触5mg/kg可卡因的所有动物在测试期间（未给予可卡因时）的活动均少于未配对接触实验装置和可卡因的对照，且在这方面C40后代与LC和PF后代并无差异。因此，尽管妊娠期间接触可卡因的大鼠对可卡因缺乏条件性位置偏爱，但它们在条件反射期间的测试行为的一个方面仍显示出可卡因的作用。这些动物缺乏可卡因诱导的位置偏爱的可能解释包括学习缺陷或可卡因作为奖赏的效力变化。
