Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, FL, United States.
Department of Psychology, University of Michigan, Ann Arbor, MI, United States.
Neurosci Biobehav Rev. 2021 Mar;122:176-189. doi: 10.1016/j.neubiorev.2020.11.017. Epub 2021 Jan 14.
Emerging plans for travel to Mars and other deep space destinations make it critical for us to understand how spaceflight affects the human brain and behavior. Research over the past decade has demonstrated two co-occurring patterns of spaceflight effects on the brain and behavior: dysfunction and adaptive plasticity. Evidence indicates the spaceflight environment induces adverse effects on the brain, including intracranial fluid shifts, gray matter changes, and white matter declines. Past work also suggests that the spaceflight environment induces adaptive neural effects such as sensory reweighting and neural compensation. Here, we introduce a new conceptual framework to synthesize spaceflight effects on the brain, Spaceflight Perturbation Adaptation Coupled with Dysfunction (SPACeD). We review the literature implicating neurobehavioral dysfunction and adaptation in response to spaceflight and microgravity analogues, and we consider pre-, during-, and post-flight factors that may interact with these processes. We draw several instructive parallels with the aging literature which also suggests co-occurring neurobehavioral dysfunction and adaptive processes. We close with recommendations for future spaceflight research, including: 1) increased efforts to distinguish between dysfunctional versus adaptive effects by testing brain-behavioral correlations, and 2) greater focus on tracking recovery time courses.
新兴的火星和其他深空目的地旅行计划使我们必须了解太空飞行如何影响人类大脑和行为。过去十年的研究表明，太空飞行对大脑和行为有两种同时发生的影响模式：功能障碍和适应性可塑性。有证据表明，太空飞行环境会对大脑造成不良影响，包括颅内液流转移、灰质变化和白质下降。过去的工作还表明，太空飞行环境会引起适应性的神经效应，如感觉重新加权和神经补偿。在这里，我们引入了一个新的概念框架来综合太空飞行对大脑的影响，即太空飞行干扰适应与功能障碍耦合（SPACeD）。我们回顾了文献中涉及到的神经行为功能障碍和适应对太空飞行和微重力模拟的反应，同时考虑了可能与这些过程相互作用的飞行前、飞行中和飞行后因素。我们与衰老文献进行了一些有益的类比，衰老文献也表明同时存在神经行为功能障碍和适应性过程。最后，我们对未来的太空飞行研究提出了建议，包括：1）通过测试大脑-行为相关性，加大努力区分功能障碍与适应性效应；2）更加关注跟踪恢复时间过程。
