Julius H. Comroe, Jr., distinguished lecture: central chemoreception: then ... and now

Area of Science:

• Physiology
• Neuroscience

Background:

• The lecture reviews current understanding of central chemoreception for carbon dioxide/pH (CO₂/pH).
• It examines the neural and glial elements involved in sensing CO₂/pH.
• The role of various hindbrain nuclei, including the retrotrapezoid nucleus and locus ceruleus, is discussed.

Discussion:

• Chemoreception involves multiple sites in the hindbrain, not just a single center.
• There is a significant nonadditive interaction between central chemoreception and peripheral carotid body input.
• Anesthesia-free studies are crucial for accurate physiological data.

Key Insights:

• CO₂/pH sensing occurs at numerous brainstem locations, involving complex neuronal and glial networks.
• Physiological responses to CO₂/pH extend beyond ventilation to include airway resistance, arousal, and blood pressure.
• The interplay between central and peripheral chemosensory information is complex and nonadditive.

Outlook:

• Future research should focus on elucidating the precise mechanisms within identified brainstem nuclei.
• Investigating the integrated physiological outputs (ventilation, airway resistance, arousal, blood pressure) is essential.
• Continued emphasis on data from conscious, unstressed animal models will advance the field.