Department of Neuroradiology, Hospital of the University of Munich (LMU), Marchioninistrasse 15, D-81377, Munich, Germany.
Radiologisches Zentrum München-Pasing, Pippinger Str. 25, D-81245 Munich, Germany.
Life Sci Space Res (Amst). 2020 Feb;24:83-90. doi: 10.1016/j.lssr.2019.09.004. Epub 2019 Oct 15.
Long-term confinement is known to be a stressful experience with multiple psycho-physiological effects. In the MARS500 project, a real-time simulation of a space-flight to Mars conducted in a hermetically isolated habitat, effects of long-term confinement could be investigated in a unique manner. The aim of this study was to evaluate effects of long-term-confinement on brain cytoarchitecture.
MATERIAL & METHODS: The participants of the MARS500 project underwent 3T-MR imaging including a dedicated DTI-sequence before the isolation, right after ending of confinement and 6 months after the experiment. Voxelwise statistical analysis of the DTI data was carried out using tract-based-spatial statistics, comparing an age-matched control group.
At all three sessions, significant lower fractional anisotropy (FA) than in controls was found in the anterior parts of the callosal body of the participants. Furthermore, after ending of confinement a wide-spread FA reduction could be seen in the right hemisphere culminating in the temporo-parietal-junction-zone. All these areas with decreased FA predominantly showed an elevated radial diffusivity and mean diffusivity while axial diffusivity was less correlated.
Long-term confinement does have measurable effects on the microstructure of the brain white matter. We assume effects of sensory deprivation to account for the regional FA reductions seen in the right TPJ. The differences in the Corpus callosum were interpreted as due to preliminary conditions, e.g. personality traits or training effects. FA and radial diffusivity were the predominant DTI parameters with significant changes, suggesting underlying processes of myelin plasticity.
长期禁闭被认为是一种具有多种心理生理影响的应激体验。在 MARS500 项目中，通过在密封隔离的栖息地中实时模拟火星飞行，可以以独特的方式研究长期禁闭的影响。本研究旨在评估长期禁闭对大脑细胞结构的影响。
MARS500 项目的参与者在隔离前、隔离结束后和实验结束后 6 个月接受了 3T-MRI 成像，包括专门的 DTI 序列。使用基于束的空间统计学对 DTI 数据进行体素分析，将其与年龄匹配的对照组进行比较。
在所有三个阶段，参与者胼胝体前部的各向异性分数（FA）均明显低于对照组。此外，在禁闭结束后，可以在右半球看到广泛的 FA 减少，最终达到颞顶联合区。所有这些 FA 降低的区域主要表现为径向弥散度和平均弥散度升高，而轴向弥散度相关性较低。
长期禁闭确实对大脑白质的微观结构有可测量的影响。我们假设感觉剥夺的影响解释了右 TPJ 中观察到的区域 FA 减少。胼胝体的差异被解释为初步条件的结果，例如个性特征或训练效果。FA 和径向弥散度是具有显著变化的主要 DTI 参数，表明存在髓鞘可塑性的潜在过程。
