Modulation of Tracheobronchial Cough by Sensory Input: In Vivo Experiments and Model Simulations

Abstract

Cough can be modeled using a network composed of known elements of the respiratory pattern generator; yet the regulation of cough in response to afferent input differs from breathing. Computer simulations of cough based on multineuron recordings in decerebrated cats show similarities and differences with in vivo cough regulation. (i) Integrated cough inspiratory and expiratory motoneuron burst amplitudes are highly correlated in simulations and in decerebrated but not anesthetized cats. (ii) Predictions from simulations of baroreceptor effects on breathing suggested that transiently elevated blood pressure would reduce cough number and cough‐related inspiratory, and expiratory amplitudes as well as prolong cough cycle durations. These effects were seen in both simulations of cough‐baroreceptor stimulation and in vivo. However, preliminary analysis suggests that expulsive phase durations during cough were prolonged in simulations but not in vivo. (iii) Simulations that incorporated linear variations of sensory afferent discharge or conductance of the first central synapse revealed more positive relationships between spatiotemporal features of the cough motor pattern than were seen in vivo. The results support functional “filtering” of sensory afferent input to the cough pattern generator by elements subsequent to the first central synapse. Supported by HL103415, HL89104.