We investigate oscillation regularity of a noise-driven system modeled with a slow afterhyperpolarizing adaptation current (AHP) composed of multiple-exponential relaxation time scales.
Sufficiently separated slow and fast AHP time scales (biphasic decay) cause a peak in oscillation
irregularity for intermediate input currents I, with relatively regular oscillations for small and large
currents. An analytic formulation of the system as a stochastic escape problem establishes that the
phenomena is distinct from standard forms of coherence resonance. Our results explain data on the
oscillation regularity of the pre-Bo¨tzinger complex, a neural oscillator responsible for inspiratory
breathing rhythm generation in mammals.