What are chemoreceptor neurons and why should we care?
Humans and all air-breathing animals breathe to get rid of excess CO2 produced by metabolism and to take in O2 needed to metabolize food and produce energy. Sensory feedback from CO2 and O2 chemoreceptor neurons is absolutely necessary to sustain breathing and therefore life. Of course, none of us thinks about breathing! To manage this breathing behavior automatically, we have chemoreceptor neurons that monitor CO2 and O2 levels in the body, and which respond to these levels by producing “spike trains” of electrical activity — essentially 0/1 plots of electical signals — that are propagated along the axons of nerve cells and provide negative feedback signals to the brain to control the depth and rate of breathing. Failure of neural control of breathing leaves patients unable to breathe on their own, and dependent on mechanical ventilation. Breathing (respiratory) failure severely reduces quality of life and puts the patient in imminent danger of death. Unfortunately, failure of CO2
