Breathing is regulated by a host of arousal and sleep-wake state-dependent neuromodulators in order to maintain respiratory homeostasis. Modulators such as acetylcholine, norepinephrine, histamine, serotonin (5-HT), adenosine triphosphate (ATP), substance P, somatostatin, bombesin, orexin, and leptin can serve complementary or off-setting functions depending on the target cell type and signalling mechanisms engaged. Abnormalities in any of these modulatory mechanisms can destabilize breathing, suggesting modulatory mechanisms are not overly redundant but rather work in concert to maintain stable respiratory output. The present review focuses on the modulation of a specific cluster of neurons located in the ventral medullary surface, named retrotrapezoid nucleus, that is activated by changes in tissue CO2/H+ and regulates several aspects of breathing, including inspiration and active expiration.
State‐dependent regulation of breathing by the retrotrapezoid nucleus (872.10)
