Hypoxia and Hyperoxia Alter Brain Metabolism in Awake Human

Feng Xu¹, Uma Yezhuvath¹, Peiying Wang¹, Hanzhang Lu¹

Many studies tried to understand how neural activity change vascular parameters, but little attention was received to whether gas content changes in blood would reversely alter neural activity. To investigate such an effect, we used a recently developed MRI technique to quantify global cerebral metabolic rate of oxygen (CMRO2) under hypoxia and hyperoxia. Our data suggest that a change in arterial oxygen content can modulate brain metabolism in a dose-dependent manner, with hypoxia increasing CMRO2 and hyperoxia decreasing it. Therefore, in addition to the well-known forward neurovascular coupling, the reverse coupling may be important in the regulation of brain function.