Respiratory Rhythm Generation: The Whole Is Greater Than the Sum of the Parts

Breathing is a continuous behavior essential for life in mammals and one of the few behaviors that can be studied in vivo in intact animals awake, anesthetized or decerebrated and in highly reduced in vitro and in situ preparations. The preBotzinger complex (preBotC) is a small nucleus in the brainstem that plays an essential role in normal breathing and is widely accepted as the site necessary and sufficient for generation of the inspiratory phase of the respiratory rhythm. Substantial advances in understanding the anatomical and cellular basis of respiratory rhythmogenesis have arisen from in vitro and in vivo studies in the past 25 years; however, the underlying cellular mechanisms remain unknown.