The Role of the Cerebellum on the Control of Tracheobronchial Cough in Spontaneously Breathing Cats

Abstract

Prior work exploring the role of the cerebellum in cough has been limited to paralyzed preparations. Xu et al. (1997) found in paralyzed, artificially ventilated, and decerebrated cats that after cerebellectomy cough number and expiratory magnitude was reduced with no change in phrenic bursting. However, we hypothesized that the cerebellum would have a different effect on coughing in unparalyzed animals than what was observed by Xu et al. (1997) due to significant behavior‐specific feedback. Cough was induced by mechanical stimulation of the tracheobronchial airways in anesthetized, spontaneously breathing adult cats (n=6). Electromyograms (EMGs) were recorded from upper airway, chest wall and abdominal respiratory muscles. Cough trials were performed before and after a total cerebellectomy. Post cerebellectomy, we observed a decrease in respiratory rate (23±2 to 18±2 breaths/min, p = 0.02) as a result of an increase in the duration of the expiratory phase of breathing (1.5±0.2 to 2.3±0.3 seconds, p = 0.03) and increase in total cycle time (2.7±0.3 to 3.5±0.3 seconds, p = 0.04). Cerebellectomy had no effect on cough number, frequency, esophageal pressure, or bout duration. Post cerebellectomy, there was a significant increase in thoracic inspiratory EMG magnitudes during cough. When normalized to the maximal control effort, on average diaphragm EMG increased from 67±6% to 81±9% (p = 0.04). The left parasternal EMG increased from 70±5% to 98±8% (p = 0.04), and the right parasternal EMG increased from 71± 4% to 93±5% (p = 0.01). The average thyroarytenoid EMG amplitude increased post cerebellectomy (66±6% to 118±26%, p = 0.03), with no change observed in the posterior cricoarytenoid EMG. No significant changes were observed in cough phase durations. Changes in cough EMG magnitudes suggest that the cerebellum modulates cough motor drive, but not cough phase timing or number of behaviors in response to mechanical stimuli in this model. These results suggest an important role of the cerebellum and behavior‐related sensory feedback in the regulation of coughing.Support or Funding InformationSupported by NIH SPARC OT2OD023854‐01 and HL131716.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.