Stewart Paul, Reihman Jacqueline, Gump Brooks, Lonky Edward, Darvill Thomas, Pagano James
304 Mahar Hall, State University of New York at Oswego, Oswego, NY 13126, USA.
Neurotoxicol Teratol. 2005 Nov-Dec;27(6):771-80. doi: 10.1016/j.ntt.2005.07.003. Epub 2005 Sep 28.
We previously reported a relationship between prenatal PCB exposure and impulsive (excessive) responding on a continuous performance task in children at 4 1/2 years of age [P.W. Stewart, S. Fitzgerald, J. Reihman, B. Gump, E. Lonky, T. Darvill, J. Pagano, P. Hauser, Prenatal PCB exposure, the corpus callosum, and response inhibition, Environmental Health Perspectives 111 (13) (2003b) 1670-1677.]. The current study investigated the stability of this effect at 8 and 9 1/2 years of age. We tested the hypothesis that PCB-related impulsive responding might be a function of impaired response inhibition. Children (n=202) enrolled in the Oswego Children's Study were tested at 8 years of age using the NES2 Continuous Performance Test (CPT). This was followed by a series of Extended Continuous Performance Tests (E-CPT) at 9 1/2 years of age, designed to dissociate response inhibition from sustained attention. After taking into account more than 50 measured covariables, including maternal IQ, maternal sustained attention and maternal response inhibition, results revealed PCB-related associations with impulsive responding at both testing ages. At 8 years of age, prenatal PCB exposure was associated with increased impulsive responding on the CPT. At 9 1/2 years of age, E-CPT testing clearly indicated that the PCB-related impulsive responding was due to impaired response inhibition and not impaired sustained attention. These results were significant after extensive and rigorous control for multiple potential confounders, including several non-PCB contaminants (prenatal MeHg, DDE, HCB, and pre- and postnatal Pb). These data are consistent with, and in fact predicted by, several studies in PCB-exposed animals.
我们之前曾报道过产前多氯联苯暴露与4.5岁儿童在持续性操作任务中的冲动（过度）反应之间的关系[P.W. 斯图尔特、S. 菲茨杰拉德、J. 赖曼、B. 冈普、E. 隆基、T. 达维尔、J. 帕加诺、P. 豪泽，《产前多氯联苯暴露、胼胝体与反应抑制》，《环境健康展望》111 (13) (2003b) 1670 - 1677。]。本研究调查了这种效应在8岁和9.5岁时的稳定性。我们检验了以下假设：与多氯联苯相关的冲动反应可能是反应抑制受损的一种表现。对参加奥斯威戈儿童研究的202名儿童在8岁时使用NES2持续性操作测试（CPT）进行了测试。随后在9.5岁时进行了一系列扩展持续性操作测试（E - CPT），旨在区分反应抑制和持续注意力。在考虑了50多个测量的协变量，包括母亲的智商、母亲的持续注意力和母亲的反应抑制之后，结果显示在两个测试年龄都存在与多氯联苯相关的冲动反应关联。在8岁时，产前多氯联苯暴露与CPT上冲动反应增加有关。在9.5岁时，E - CPT测试清楚地表明，与多氯联苯相关的冲动反应是由于反应抑制受损而非持续注意力受损。在对包括几种非多氯联苯污染物（产前甲基汞、滴滴涕、六氯苯以及产前和产后铅）在内的多个潜在混杂因素进行广泛而严格的控制之后，这些结果具有显著意义。这些数据与在多氯联苯暴露动物身上进行的几项研究一致，实际上也是由这些研究所预测的。
