Fig. 2.

Closed-loop bursting persists in the absence of the isolated CPG bursting mechanism. A: black traces show bursts of action potentials (V, top) in the closed-loop model with persistent sodium channel inactivation (h, middle) as a dynamic variable and a dynamic g_tonic (bottom) in response to changes in $\mathrm{P}{\mathrm{a}}_{\mathrm{O}}{}_{{}_2}$. B: blue traces show bursting in the open-loop model with h as a dynamic variable and g_tonic set as a static parameter. C: red traces show bursting in a version of the closed-loop model where h is set as a static parameter. This illustrates that the dynamical mechanism responsible for bursting in the open-loop model (slow h dynamics) is not required for bursting in the closed-loop model.