Background

Prenatal alcohol exposure (PAE) affects early brain development and has been associated with hippocampal damage. Animal models of PAE have suggested that some subfields of the hippocampus may be more susceptible to damage than others. Recent advances in structural MRI processing now allow us to examine the morphology of hippocampal subfields in humans with PAE.

Method

Structural MRI scans were collected from 40 children with PAE and 39 typically developing children (ages 8–16). The images were processed using the Human Connectome Project Minimal Preprocessing Pipeline (v4.0.1) and the Hippocampal Subfields package (v21) from FreeSurfer. Using a large dataset of typically developing children enrolled in the Human Connectome Project in Development (HCP-D) for normative standards, we computed age-specific volumetric z-scores for our two samples. Using these norm-adjusted hippocampal subfield volumes, comparisons were performed between children with PAE and typically developing children, controlling for total intracranial volume. Lastly, we investigated whether subfield volumes correlated with episodic memory (i.e., Picture Sequence Memory test of the NIH toolbox).

Results

Five subfields had significantly smaller adjusted volumes in children with PAE than in typically developing controls: CA1, CA4, subiculum, presubiculum, and the hippocampal tail. Subfield volumes were not significantly correlated with episodic memory.

Conclusions

The results suggest that several regions of the hippocampus may be particularly affected by PAE. The finding of smaller CA1 volumes parallels previous reports in rodent models. The novel findings of decreased volume in the subicular cortex, CA4 and the hippocampal tail suggest avenues for future research.

中文翻译：

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胎儿酒精谱系障碍儿童的海马亚区异常和记忆功能

背景

产前酒精暴露 (PAE) 会影响早期大脑发育，并与海马损伤有关。PAE 的动物模型表明，海马体的某些亚区可能比其他区更容易受到损伤。结构 MRI 处理的最新进展现在使我们能够检查 PAE 人类海马亚区的形态。

方法

从 40 名患有 PAE 的儿童和 39 名正常发育的儿童（8-16 岁）收集了结构 MRI 扫描。图像使用 Human Connectome Project Minimal Preprocessing Pipeline (v4.0.1) 和来自 FreeSurfer 的 Hippocampal Subfields 包 (v21) 进行处理。使用在人类连接组发展项目 (HCP-D) 中注册的大型发育儿童数据集作为规范标准，我们为我们的两个样本计算了特定年龄的体积 z 分数。使用这些经规范调整的海马亚区体积，在 PAE 儿童和正常发育儿童之间进行比较，控制总颅内体积。最后，我们调查了子场体积是否与情景记忆相关（即 NIH 工具箱的图片序列记忆测试）。

结果

PAE 儿童的五个子区域的调整体积明显小于正常发育的对照组：CA1、CA4、下突、前下突和海马尾。子场体积与情景记忆没有显着相关性。

结论

结果表明海马体的几个区域可能特别受到 PAE 的影响。较小的 CA1 体积的发现与之前在啮齿动物模型中的报告相似。下皮层、CA4 和海马尾部体积减少的新发现为未来的研究提供了途径。