Levin E D, Seidler F J
Department of Psychiatry, Duke University Medical Center, Durham, North Carolina 27710.
Neurotoxicology. 1993 Spring;14(1):23-8.
Prenatal cocaine exposure in humans is associated with a variety of adverse neurobehavioral effects. In the rat, in utero cocaine exposure has been shown to elicit learning impairment during early postnatal development. However, little research has focused on the persistence of these behavioral disruptions. The current study examines the long-term effects of prenatal cocaine exposure on learning performance during young adulthood. Fetal cocaine exposure evoked differential effects in male and female rats on radial-arm maze learning performance. Cocaine-treated females showed significantly impaired choice accuracy during acquisition of radial-arm maze performance when compared to control females. In contrast, cocaine-treated males showed no impairment and in fact showed significantly improved performance on one measure of choice accuracy. For both sexes, this effect was apparent during the final third of acquisition. No evidence was found to suggest altered sensitivity to anticholinergic drugs. While both nicotinic and muscarinic cholinergic antagonists caused significant impairments in memory performance, control and cocaine-exposed rats were effected equally. Single doses of these drugs which caused moderate memory deficits were chosen for use in the current study. The entire dose range should be evaluated to determine the relative sensitivity of cocaine-exposed and control animals to these drugs. The results of this study indicate that there are cognitive effects of prenatal cocaine exposure which persist into adulthood and the sex of the offspring seems to be critical.
人类产前接触可卡因与多种不良神经行为影响有关。在大鼠中，子宫内接触可卡因已被证明会在出生后早期发育过程中引发学习障碍。然而，很少有研究关注这些行为干扰的持续性。当前的研究考察了产前接触可卡因对成年早期学习表现的长期影响。胎儿期接触可卡因对雄性和雌性大鼠的放射状臂迷宫学习表现产生了不同的影响。与对照雌性大鼠相比，经可卡因处理的雌性大鼠在获得放射状臂迷宫表现的过程中，选择准确性显著受损。相比之下，经可卡因处理的雄性大鼠没有表现出受损，事实上，在一项选择准确性指标上表现出显著改善。对于两性而言，这种影响在习得的最后三分之一阶段很明显。没有证据表明对抗胆碱能药物的敏感性发生改变。虽然烟碱型和毒蕈碱型胆碱能拮抗剂都会导致记忆表现显著受损，但对照大鼠和接触可卡因的大鼠受到的影响是相同的。本研究选择了能引起中度记忆缺陷的单剂量这些药物。应该评估整个剂量范围，以确定接触可卡因的动物和对照动物对这些药物的相对敏感性。这项研究的结果表明，产前接触可卡因存在持续到成年期的认知影响，并且后代的性别似乎至关重要。
