Zhang Xinjuan, Kang Taishan, Liu Yanqiu, Yuan Fengjuan, Li Minglu, Lin Jianzhong, Zhang Jiaxing
Institute of Brain Diseases and Cognition, School of Medicine, Xiamen University, Xiamen 361102, China.
Department of Radiology, Zhongshan Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen 361004, China.
Brain Sci. 2022 May 31;12(6):724. doi: 10.3390/brainsci12060724.
Damage to the visual cortex structures after high altitude exposure has been well clarified. However, changes in the neuronal activity and functional connectivity (FC) of the visual cortex after hypoxia/reoxygenation remain unclear. Twenty-three sea-level college students, who took part in 30 days of teaching at high altitude (4300 m), underwent routine blood tests, visual behavior tests, and magnetic resonance imaging scans before they went to high altitude (Test 1), 7 days after they returned to sea level (Test 2), as well as 3 months (Test 3) after they returned to sea level. In this study, we investigated the hematological parameters, behavioral data, and spontaneous brain activity. There were significant differences among the tests in hematological parameters and spontaneous brain activity. The hematocrit, hemoglobin concentration, and red blood cell count were significantly increased in Test 2 as compared with Tests 1 and 3. As compared with Test 1, Test 3 increased amplitudes of low-frequency fluctuations (ALFF) in the right calcarine gyrus; Tests 2 and 3 increased ALFF in the right supplementary motor cortex, increased regional homogeneity (ReHo) in the left lingual gyrus, increased the voxel-mirrored homotopic connectivity (VMHC) value in the motor cortex, and decreased FC between the left lingual gyrus and left postcentral gyrus. The color accuracy in the visual task was positively correlated with ALFF and ReHo in Test 2. Hypoxia/reoxygenation increased functional connection between the neurons within the visual cortex and the motor cortex but decreased connection between the visual cortex and motor cortex.
高海拔暴露后视觉皮层结构的损伤已得到充分阐明。然而，缺氧/复氧后视觉皮层的神经元活动和功能连接（FC）变化仍不清楚。23名来自海平面地区的大学生参加了在高海拔（4300米）地区为期30天的教学活动，在前往高海拔地区之前（测试1）、返回海平面7天后（测试2）以及返回海平面3个月后（测试3），他们接受了常规血液检查、视觉行为测试和磁共振成像扫描。在本研究中，我们调查了血液学参数、行为数据和自发性脑活动。血液学参数和自发性脑活动在各测试之间存在显著差异。与测试1和测试3相比，测试2中的血细胞比容、血红蛋白浓度和红细胞计数显著增加。与测试1相比，测试3中右侧距状回的低频波动幅度（ALFF）增加；测试2和测试3中右侧辅助运动皮层的ALFF增加，左侧舌回的局部一致性（ReHo）增加，运动皮层中的体素镜像同伦连接（VMHC）值增加，并且左侧舌回与左侧中央后回之间的FC降低。视觉任务中的颜色准确性与测试2中的ALFF和ReHo呈正相关。缺氧/复氧增加了视觉皮层内神经元与运动皮层之间的功能连接，但降低了视觉皮层与运动皮层之间的连接。
