The importance of a specific group of neurons found in a region of the brain known as the retrotrapezoid nucleus (RTN) in detecting changes in carbon dioxide (CO2) levels and in modulating the activity of the neuronal groups that control respiratory activity has been confirmed by researchers. The group's work has demonstrated that the respiratory changes caused by the increase in CO2 levels are compromised during the occurrence of selective destruction of the RTN neurons that express Phox2b.