What is the topic of this review? Cerebrovascular reactivity to CO is a principle factor in determining ventilatory responses to CO through the role reactivity plays in determining cerebral extra- and intra-cellular pH. What advances does it highlight? Recent animal evidence suggests central chemoreceptor vasculature may demonstrate regionally heterogenous cerebrovascular reactivity to CO , potentially as a protective mechanism against excessive CO washout from the central chemoreceptors, thereby allowing ventilation to reflect the systemic acid-base balance needs (respiratory changes in PaCO ) rather than solely the cerebral needs. Ventilation per se does not influence cerebrovascular reactivity independent of changes in PaCO .
Alveolar ventilation and cerebral blood flow are both predominantly regulated by arterial blood gases, especially arterial PCO , and so are intricately entwined. In this review, the fundamental mechanisms underlying cerebrovascular reactivity and central chemoreceptor control of breathing are covered. We discuss the interaction of cerebral blood flow and its reactivity with the control of ventilation and ventilatory responsiveness to changes in PCO , as well as the lack of influence of ventilation itself on cerebrovascular reactivity. We briefly summarize the effects of arterial hypoxaemia on the relationship between ventilatory and cerebrovascular response to both PCO and PO . We then highlight key methodological considerations regarding the interaction of reactivity and ventilatory sensitivity, including: regional heterogeneity of cerebrovascular reactivity; a pharmacological approach for the reduction of cerebral blood flow; reactivity assessment techniques; the influence of mean arterial blood pressure; and sex-related differences. Finally, we discuss ventilatory and cerebrovascular control in the context of high altitude and congestive heart failure. Future research directions and pertinent questions of interest are highlighted throughout. This article is protected by copyright. All rights reserved.

This article is protected by copyright. All rights reserved.