Patterns of respiratory-related membrane potential changes recorded from nonantidromically activated neurons in the ventral respiratory group of the rat. I-Dec, Decrementing inspiratory; I-All, constantly discharging inspiratory; I-Aug, augmenting inspiratory;E-Dec, decrementing expiratory;E-Decearly, early onset expiratory-decrementing; E-Aug, augmenting expiratory.Top trace in each panel is membrane potential (action potentials are clipped); bottom trace is phrenic nerve activity.