全世界每年都有大量人群往返于高原和平原。当适应了高原环境的人群进入平原后，机体将面临高原脱适应反应的威胁。我们前期研究显示高原世居藏族和移居汉族人群的脑发生了重塑。本项目进一步观察这两类人群进入平原后脑脱适应初期急性反应和后期恢复程度。针对人群的研究运用磁共振成像和脑电记录，首先观察脑结构（皮层厚度和体积、白质纤维水分子弥散、铁沉积、血流和血管结构）和脑功能（静息和任务刺激状态）的变化；其次分析脱适应症状程度、血浆皮质醇、血液和心肺功能分别与脑测量值的相关性以及脑脱适应急性反应程度与后期恢复水平的关联。最后行为测试用来判断脑结构和功能改变的意义。另一方面，建立模拟高原移居人群小鼠模型及通过基因突变模拟高原世居人群小鼠模型来分析脑白质改变的组织、细胞和分子机制。本项目将揭示脑高原脱适应反应规律并建立其反应程度和恢复的预测指标，其结果对防治脱适应带来的健康问题具有重要理论指导意义。

Every year, a large number of people in the world travel to and fro between high-altitude (HA) and lowland. People who have adapted HA environment will suffer from deadaptation to HA when they descend to lowland. The brain modifications of Tibetans and Han immigrants on Qinghai-Tibet Plateau have been revealed in our previous studies. In the present study, we further observe the acute responses and recover levels of brains during the initial stage and during the later period, respectively, in HA Tibetans and Han immigrants when they descend to lowland. Magnetic Resonance Imaging and (MRI) and electroencephalogram (EEG) are used firstly to observe the brain structures (cortex thickness and volume, water diffusion of white matter fiber, iron deposition, blood flow, and vascular structure) and brain functions (resting-state and task-activated neuronal activities). Secondly, correlation of the changed brain structures and functions with the level of deadaptation, plasma cortisol, hematological measurements, and cardiovascular and pulmonary functions, as well as correlation of brain responses during the initial stage with recover during the later period are analyzed. Finally, behavioral tests are used to estimate the significance of the changes of brain structures and functions. In the other aspect, mice models simulating HA immigrants and gene-knockout mice models simulating HA natives are used for the mechanism studies of white matter on tissue, cell, and molecular levels. Our study will clarify the law of brain de-adaptation responses in different HA populations, and thus establish the predictive index of brain de-adaptation responses. The results of our study may be helpful to the valid prediction, prevention, and cure of body de-adaptation.