Key Laboratory of Extreme Environmental Medicine, Ministry of Education of China, Army Medical University, Chongqing, China.
Department of Medical Imaging, College of Biomedical Engineering, Army Medical University, Chongqing, China.
Brain Behav. 2022 Dec;12(12):e2776. doi: 10.1002/brb3.2776. Epub 2022 Nov 2.
Inadequate oxygen availability may lead to impairment of neurocognitive functions. The aim of the present study was to investigate the effect of acute high-altitude exposure on the cerebral hemodynamic response and working memory.
The same subjects performed working memory exercises with forward and backward digit span tasks both under normal oxygen conditions and in large simulated hypobaric hypoxia chambers, and a series of physiological parameters were evaluated. Functional near-infrared spectroscopy was used to measure cerebral blood flow changes in the dorsolateral prefrontal cortex (DLPFC) during the tasks.
Compared with normoxic conditions, under hypoxic conditions, the heart rate and blood pressure increased, blood oxygen saturation decreased significantly, and the forward task had similar accuracy and response time, while the backward task had lower accuracy and longer response time. Neuroimaging analysis showed increased activation in the DLPFC during the forward task and deactivation during the backward task under hypobaric hypoxia conditions.
Acute high-altitude exposure leads to physiological adaptations. The abnormal hemodynamic responses of the DLPFC to hypoxia at low pressure reveal the disruption of neurocognitive function by acute high-altitude exposure, which compromises complex cognitive functions, and provides a promising application for functional near infrared spectroscopy in the exploration of neural mechanisms in the brain during high-altitude exposure.
氧气供应不足可能导致神经认知功能受损。本研究旨在探讨急性高原暴露对大脑血液动力学反应和工作记忆的影响。
同一批受试者在正常氧条件下和大型模拟低压缺氧室中进行向前和向后数字跨度任务的工作记忆练习，并评估了一系列生理参数。功能近红外光谱用于测量任务期间背外侧前额叶皮层（DLPFC）的脑血流变化。
与正常氧条件相比，在缺氧条件下，心率和血压升高，血氧饱和度显著下降，向前任务的准确性和反应时间相似，而向后任务的准确性较低，反应时间较长。神经影像学分析显示，在低压缺氧条件下，向前任务时 DLPFC 激活增加，向后任务时去激活。
急性高原暴露导致生理适应。低压缺氧时 DLPFC 的异常血液动力学反应揭示了急性高原暴露对神经认知功能的破坏，这会影响复杂的认知功能，为功能近红外光谱在探索高原暴露期间大脑的神经机制方面提供了有前途的应用。
