Department of Psychology, University of Maryland, College Park, Maryland, USA.
Hippocampus. 2020 Oct;30(10):1098-1111. doi: 10.1002/hipo.23218. Epub 2020 Jun 4.
Early childhood is characterized by vast changes in behaviors supported by the hippocampus and an increased susceptibility of the hippocampus to environmental influences. Thus, it is an important time to investigate the development of the hippocampus. Existing research suggests subregions of the hippocampus (i.e., head, body, tail) have dissociable functions and that the relations between subregions and cognitive abilities vary across development. However, longitudinal research examining age-related changes in subregions in humans, particularly during early childhood (i.e., 4-6 years), is limited. Using a large sample of 184 healthy 4- to 8-year-old children, the present study is the first to characterize developmental changes in hippocampal subregion volume from early- to mid-childhood. Results reveal differential developmental trajectories in hippocampal head, body, and tail during this period. Specifically, head volume showed a quadratic pattern of change, and both body and tail showed linear increases, resulting in a pattern of cubic change for total hippocampal volume. Further, main effects of sex on hippocampal volume (males > females) and hemispheric differences in developmental trajectories were observed. These findings provide an improved understanding of the development of the hippocampus and have important implications for research investigating a range of cognitive abilities and behaviors.
儿童早期的行为变化很大，这一过程受到海马体的支持，并且海马体对外界环境的影响更加敏感。因此，这是研究海马体发育的重要时期。现有研究表明，海马体的各个亚区（即头部、体部和尾部）具有不同的功能，并且亚区与认知能力之间的关系在不同的发育阶段也有所不同。然而，目前关于人类（尤其是 4-6 岁的儿童）海马体亚区随年龄变化的纵向研究还很有限。本研究使用了一个包含 184 名健康 4 至 8 岁儿童的大样本，首次对儿童早期至中期的海马体亚区体积的发育变化进行了描述。研究结果表明，在此期间，海马体头部、体部和尾部的发育轨迹存在差异。具体来说，头部体积呈二次变化模式，而体部和尾部则呈线性增长，导致总海马体体积呈三次变化模式。此外，研究还观察到了性别对海马体体积（男性>女性）的主要影响，以及在发育轨迹上的半球差异。这些发现提高了我们对海马体发育的认识，对于研究一系列认知能力和行为具有重要意义。
