Breathing automaticity and CO2 regulation are inseparable neural processes. The
retrotrapezoid nucleus (RTN), a group of glutamatergic neurons that express the
transcription factor Phox2b, may be a crucial nodal point through which breathing
automaticity is regulated to maintain CO2 constant. This review updates the analysis
presented in prior publications. Additional evidence that RTN neurons have central
respiratory chemoreceptor properties is presented, but this is only one of many factors that …