Background

Organophosphate pesticides (OP) are widely used for both agricultural and domestic purposes. Epidemiological studies suggest neurotoxicity in children after exposure to organophosphates pesticides (OP) at low levels but possible mechanism is still unclear.

Objectives

We aimed at investigating the effects of prenatal exposure to OPs on inhibitory control of 10–12 year-old-children assessed by a motor inhibition task during functional magnetic resonance imaging (fMRI).

Methods

Ninety-five children from the PELAGIE cohort (Brittany-France, from 2002) underwent a fMRI examination during which inhibition was assessed by a Go/No-Go task. Task performance was assessed by average response latency, commission rate and composite performance score (PS). Whole brain activation was estimated by modeling the hemodynamic response related to inhibition demand and successful inhibition. OP exposure was assessed by measuring six dialkylphosphate (DAP) metabolites in the urine of women in early pregnancy (<19 WG). Concentrations were summed to obtain overall levels of diethylphosphate (DE), dimethylphosphate (DM) and total non-specific metabolites (DAP), standardized to homogenize sampling conditions and categorized into levels of exposure: low (reference), moderate or high. Regression models were adjusted for potential cofounders considered by restriction and statistical criteria.

Results

Moderate levels of DAP were associated with a decreased commission rate (β = −6.65%, p = 0.04), indicating improved performance. Increasing levels of DM and DE were associated with decreased brain activity in the left inferior and bilateral superior frontal regions during successful inhibition. We did not observe any differential activation related to inhibitory demands.

Discussion

These results suggest that prenatal OPs may be associated with altered pattern of brain activity in regions related to inhibition among children and need to be confirmed by additional studies.

中文翻译：

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通过功能磁共振成像评估，孕妇在10至12岁时接触有机磷杀虫剂和儿童运动抑制。

背景

有机磷农药（OP）被广泛用于农业和家庭用途。流行病学研究表明，低水平接触有机磷酸盐农药（OP）后儿童的神经毒性，但可能的机制仍不清楚。

目标

我们的目的是调查功能性磁共振成像（fMRI）中通过运动抑制任务评估的产前暴露于OP的抑制控制10-12岁儿童的影响。

方法

来自PELAGIE队列（Brittany-France，来自2002年）的95名儿童接受了功能磁共振成像检查，在此过程中，通过“通过/不通过”任务评估了抑制作用。通过平均响应延迟，佣金率和综合性能评分（PS）评估任务性能。通过对与抑制需求和成功抑制有关的血液动力学反应进行建模，可以估计全脑激活。通过测量孕妇早期（<19 WG）尿液中的六种磷酸二烷基酯（DAP）代谢产物来评估OP暴露。对浓度进行求和以获得磷酸二乙酯（DE），磷酸二甲酯（DM）和总非特异性代谢物（DAP）的总水平，将其标准化以均化采样条件，并分类为暴露水平：低（参考），中度或高。

结果

中等水平的DAP与降低的佣金率相关（β= -6.65％，p = 0.04），表明性能得到改善。在成功抑制过程中，DM和DE水平的升高与左下和双侧上额叶区域的大脑活动减少有关。我们没有观察到与抑制需求有关的任何差异激活。

讨论区

这些结果表明，产前OP可能与儿童抑制相关区域的大脑活动模式改变有关，需要进一步的研究证实。