Kinsley C H, Turco D, Bauer A, Beverly M, Wellman J, Graham A L
Department of Psychology, University of Richmond, VA 23173.
Pharmacol Biochem Behav. 1994 Apr;47(4):857-64. doi: 10.1016/0091-3057(94)90288-7.
Though much attention has been devoted to the behavioral and physiological consequences of cocaine abuse in offspring, little is known regarding the effects on the maternal behavior of the cocaine-exposed dam. We examined whether cocaine affects the initiation (late pregnancy) and/or maintenance (postpartum [PP]) phases of full maternal behavior (FMB; retrieving, grouping, and crouching over six pups) in Sprague-Dawley female rats. In Experiment 1, cocaine (5.0 or 10.0 mg/kg) or saline was administered on PP day 5 or 6 and FMB scored. Both dosages significantly disrupted FMB, particularly crouching, though 10.0 mg/kg had a greater effect on FMB. Experiment 2 (using 10.0 mg/kg cocaine) examined specific elements of the disruption and found significant reductions in proportion of females engaging in FMB, as well as increases in the latencies to contact, retrieve, lick, group, and crouch over pups. In Experiment 3 osmotic pumps containing 20 mg cocaine/kg/day or saline were implanted SC in day 14 pregnant rats. FMB testing was performed on days 1-2 postpartum together with a T-maze pup-retrieval test on postpartum days 3-5. Cocaine disrupted FMB in the homecage, in general, rendering the females less attentive to young, but was without effect in the T-maze tests. Cocaine--perhaps owing to its purported dopaminergic activity--may operate through motivational mechanisms to disrupt FMB in the postpartum maintenance phase; and through effects on late pregnancy levels of prolactin (a hormone which stimulates FMB), to disrupt maternal behavior during the initiation phase.
尽管人们对可卡因滥用对后代行为和生理的影响给予了很多关注，但对于可卡因暴露的母鼠的母性行为所受影响却知之甚少。我们研究了可卡因是否会影响斯普拉格-道利雌性大鼠完全母性行为（FMB；找回、聚集并俯身在六只幼崽上）的启动阶段（妊娠晚期）和/或维持阶段（产后[PP]）。在实验1中，于产后第5天或第6天给予可卡因（5.0或10.0毫克/千克）或生理盐水，并对FMB进行评分。两种剂量均显著扰乱了FMB，尤其是俯身行为，不过10.0毫克/千克对FMB的影响更大。实验2（使用10.0毫克/千克可卡因）研究了扰乱的具体因素，发现参与FMB的雌性比例显著降低，同时接触、找回、舔舐、聚集和俯身在幼崽上的潜伏期增加。在实验3中，于妊娠第14天给怀孕大鼠皮下植入含20毫克可卡因/千克/天的渗透泵或生理盐水。在产后第1 - 2天进行FMB测试，并在产后第3 - 5天进行T迷宫幼崽找回测试。总体而言，可卡因扰乱了笼内的FMB，使雌性对幼崽的关注度降低，但在T迷宫测试中没有影响。可卡因——可能由于其所谓的多巴胺能活性——可能通过动机机制在产后维持阶段扰乱FMB；并通过影响妊娠晚期催乳素水平（一种刺激FMB的激素），在启动阶段扰乱母性行为。
