Background and Objectives

Prenatal exposure to environmental tobacco smoke (ETS) is associated with increased attention problems in children, however, the effects of such exposure on children’s brain structure and function have not been studied. Herein, we probed effects of prenatal ETS on children’s cognitive control circuitry and behavior.

Methods

Forty-one children (7–9 years) recruited from a prospective longitudinal birth cohort of non-smoking mothers completed structural and task-functional magnetic resonance imaging to evaluate effects of maternal ETS exposure, measured by maternal prenatal urinary cotinine. Attention problems and externalizing behaviors were measured by parent report on the Child Behavior Checklist.

Results

Compared to non-exposed children, exposed children had smaller left and right thalamic and inferior frontal gyrus (IFG) volumes, with large effect sizes (p-FDR < .05, Cohen’s D range from 0.79 to 1.07), and increased activation in IFG during the resolution of cognitive conflict measured with the Simon Spatial Incompatibility Task (38 voxels; peak t(25) = 5.25, p-FWE = .005). Reduced thalamic volume was associated with increased IFG activation and attention problems, reflecting poor cognitive control. Mediation analyses showed a trend toward left thalamic volume mediating the association between exposure and attention problems (p = .05).

Conclusions

Our findings suggest that maternal ETS exposure during pregnancy has deleterious effects on the structure and function of cognitive control circuitry which in turn affects attentional capacity in school-age children. These findings are consistent with prior findings documenting the effects of active maternal smoking on chidlren’s neurodevleoment, pointing to the neurotixicity of nicotine regardless of exposure pathway.

中文翻译：

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产前环境烟草烟雾暴露改变儿童的认知控制回路：初步研究

背景和目标

产前接触环境烟草烟雾 (ETS) 与儿童注意力问题增加有关，然而，这种接触对儿童大脑结构和功能的影响尚未研究。在此，我们探讨了产前 ETS 对儿童认知控制回路和行为的影响。

方法

从非吸烟母亲的前瞻性纵向出生队列中招募的 41 名儿童（7-9 岁）完成了结构和任务功能磁共振成像，以评估母亲 ETS 暴露的影响（通过母亲产前尿液可替宁测量）。注意力问题和外化行为是通过家长关于儿童行为检查表的报告来衡量的。

结果

与非暴露儿童相比，暴露儿童的左右丘脑和额下回 (IFG) 体积较小，效应量较大（p-FDR < .05，Cohen's D 范围为 0.79 至 1.07），并且 IFG 激活增加在通过 Simon 空间不相容性任务测量的认知冲突解决过程中（38 体素；峰值 t(25) = 5.25，p-FWE = .005）。丘脑体积减小与 IFG 激活增加和注意力问题相关，反映了认知控制能力差。中介分析显示左丘脑体积的趋势介导暴露和注意力问题之间的关联 (p = .05)。

结论

我们的研究结果表明，母亲在怀孕期间接触 ETS 对认知控制回路的结构和功能产生有害影响，进而影响学龄儿童的注意力能力。这些发现与先前记录母亲主动吸烟对儿童神经发育影响的研究结果一致，表明尼古丁具有神经毒性，无论暴露途径如何。