Hypoxic Signal Transduction and Compensatory Mechanisms in the Neurovascular Unit.

Hypoxic hypoxia arises from an inadequate oxygen supply to the blood, resulting in reduced arterial oxygen partial pressure and a consequent decline in oxygen diffusion into tissue cells for utilization. This condition is characterized by diminished oxygen content in the blood, while the supply of other nutrients within the blood remains normal. The brain is particularly sensitive to oxygen deficiency, with varying degrees of hypoxic hypoxia resulting in different levels of neural functional disorder. Since the brain has a specific threshold range for the perception of hypoxic hypoxia, mild hypoxic hypoxia can trigger compensatory protective responses in the brain without affecting neural function. These hypoxic compensatory responses enable the maintenance of an adequate oxygen supply and energy substrates for neurons, thereby ensuring normal physiological functions. To further understand the hypoxic compensatory mechanisms of the central nervous system (CNS), this article explores the structural features of the brain's neurovascular unit model, hypoxic signal transduction, and compensatory mechanisms.