Schneider J S, Lee M H, Anderson D W, Zuck L, Lidsky T I
Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, 1020 Locust Street, 521 JAH, Philadelphia, PA 19107, USA.
Brain Res. 2001 Mar 30;896(1-2):48-55. doi: 10.1016/s0006-8993(00)03249-2.
It is known that children of lower socioeconomic status have a disproportionately higher risk of being exposed to lead and have a more negative outcome from that exposure than children who are raised under more fortunate circumstances. Yet, little is known about how environmental factors may influence the injurious effects on the brain of a neurotoxin such as lead. The present study used an animal model of lead poisoning to examine the extent to which different environmental milieus may modify the effects of lead on the developing brain. Young rats were raised in either enriched or impoverished environments and drank either distilled water or water with lead. Lead-exposed rats raised in the impoverished environment had spatial learning deficits and significantly decreased neurotrophic factor gene expression in the hippocampus. In contrast, the animals raised in the enriched environment were significantly protected against the behavioral and neurochemical toxicity of lead. These results demonstrate that impoverished environment may accentuate while enriched environment may ameliorate neurobehavioral and neurochemical toxicity from developmental lead exposure.
众所周知，社会经济地位较低的儿童接触铅的风险极高，而且相较于成长环境较为优越的儿童，接触铅对他们产生的负面影响更大。然而，关于环境因素如何影响铅等神经毒素对大脑的损害作用，我们却知之甚少。本研究采用铅中毒动物模型，来探究不同环境背景在多大程度上可能改变铅对发育中大脑的影响。将幼鼠饲养于丰富环境或贫瘠环境中，并分别饮用蒸馏水或含铅水。饲养于贫瘠环境中的铅暴露大鼠出现空间学习缺陷，海马体中神经营养因子基因表达显著降低。相比之下，饲养于丰富环境中的动物受到铅的行为和神经化学毒性影响明显较小。这些结果表明，贫瘠环境可能会加剧，而丰富环境可能会减轻发育性铅暴露所致的神经行为和神经化学毒性。
