Computational Models of Mammalian Respiratory CPG

Abstract

Definition Rhythmic breathing movements in mammals are produced by a central pattern generator (CPG), consisting of specialized neuronal networks located in the brainstem that are capable of endoge-nously producing patterned rhythmic activity. This activity emerges from the intrinsic biophysical properties and synaptic interconnections of spatially distributed neuron populations within the pontine-medullary circuits comprising the CPG. These circuits are embedded in a larger respiratory neural control system engaging various central nervous system (CNS) and peripheral afferent inputs that regulate the neural activity patterns including the oscillation period and amplitude of the output rhythmic motor activity to adjust it to the internal and/or external environment for sensorimotor integration and physiological homeostasis of O 2 and CO 2 in the body. Computational models of the brainstem respiratory CPG that incorporate various levels of biological and mathematical detail have been in development for several decades with the objective of explaining the dynamical operation of the GPG neurons and circuits, particularly to delineate mechanisms of respiratory rhythm and pattern generation. Recent data-driven models that have explored functional architecture of the CPG circuits and advanced understanding of these mechanisms are reviewed.