Batool Shafaq, Jaswal Tejdeep, Burles Ford, Iaria Giuseppe
Canadian Space Health Research Network, Calgary, AB T2N 1N4, Canada.
NeuroLab, Department of Psychology, Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, University of Calgary, Calgary, AB T2N 1N4, Canada.
NeuroSci. 2025 Jul 25;6(3):70. doi: 10.3390/neurosci6030070.
(1) Background: Evidence from non-human animal and spaceflight analog studies have suggested that traveling to outer space could have a significant impact on the structural properties of the hippocampus, a brain region within the medial temporal lobe that is critical for learning and memory. Here, we tested this hypothesis in a group of astronauts who participated in a six-month mission in the International Space Station (ISS). (2) Methods: We collected magnetic resonance imaging (MRI) scans from a sample of 17 (9 males, 8 females) astronauts before and after the ISS mission, and calculated percent gray matter volume changes in the whole hippocampus and its (anterior, body, and posterior) subregions in both hemispheres. (3) Following the six-month mission in the ISS, we found a significantly decreased volume in the whole left hippocampus; in addition, when looking at subregions separately, we detected a significantly decreased volume in the anterior subregion of the left hippocampus and the body subregion of the right hippocampus. We also found a significantly decreased volume in the whole right hippocampus of male astronauts as compared to female astronauts. (4) Conclusions: This study, providing the very first evidence of hippocampal volumetric changes in astronauts following a six-month mission to the ISS, could have significant implications for cognitive performance during future long-duration spaceflights.
(1) 背景：来自非人类动物和太空飞行模拟研究的证据表明，前往外层空间可能会对海马体的结构特性产生重大影响，海马体是内侧颞叶内的一个脑区，对学习和记忆至关重要。在此，我们在一组参与国际空间站（ISS）为期六个月任务的宇航员中对这一假设进行了测试。(2) 方法：我们收集了17名（9名男性，8名女性）宇航员在执行ISS任务前后的磁共振成像（MRI）扫描数据，并计算了两侧海马体及其（前、体和后）亚区域的灰质体积变化百分比。(3) 在ISS执行六个月任务后，我们发现整个左侧海马体体积显著减小；此外，分别查看亚区域时，我们检测到左侧海马体前亚区域和右侧海马体体亚区域体积显著减小。我们还发现，与女性宇航员相比，男性宇航员右侧整个海马体体积显著减小。(4) 结论：这项研究首次提供了宇航员在执行为期六个月的ISS任务后海马体体积变化的证据，可能对未来长期太空飞行期间的认知表现具有重要意义。
