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How do central chemoreceptors respond to increased carbon dioxide near the medulla?

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Medical illustration of the human chest showing the lungs, diaphragm, ribs, trachea, bronchus, and bronchioles, with one lung cut away to reveal internal structures. — human respiratory system The lungs serve as the gas-exchanging organ for the process of respiration.

Central chemoreceptors are believed to be located near the ventral surface of the medulla oblongata, where they play a vital role in the control of breathing. While carbon dioxide is a powerful stimulant for ventilation, the precise mechanism of these receptors remains a subject of scientific investigation.1

When the partial pressure of carbon dioxide in arterial blood rises, it increases the acidity of the fluid surrounding cells and can easily diffuse into cells, increasing their internal acidity. It is currently unclear whether these chemoreceptors respond specifically to the extracellular or intracellular effects of this carbon dioxide-induced acidity.1

Some researchers hypothesize that the respiratory responses observed at the ventral medullary surface may not stem from dedicated chemoreceptor cells, but rather from the direct influence of carbon dioxide on vasomotor neurons that regulate blood pressure. Others suggest that the chemoreceptors responsible for sensing carbon dioxide may be more diffusely distributed throughout the brain rather than localized solely to the ventral medulla.1