What is the explanation for the suppression of the ventilatory stimulus present in subjects chronically exposed to high altitudes?

Question

Quizplus · Accepted Answer

A PaCO₂ of 20 mm Hg immediately lowers the cerebral spinal fluid (CSF) PCO₂ to 20 mm Hg and creates an even greater CSF alkalosis than it creates in the blood because the blood-brain barrier is nearly impermeable to HCO₃¯ ions. That is, as CO₂ rapidly diffuses out of the CSF in response to the low PaCO₂, HCO₃¯ cannot follow. The central chemoreceptors are thus exposed to an alkaline environment, which works to suppress their ventilatory stimulus, counteracting the peripheral chemoreceptor stimulus arising from hypoxia.

What Is the Explanation for the Suppression of the Ventilatory