Activity of inspiratory neurones of the ambiguus complex during cough in the spontaneously breathing decerebrate cat

Abstract

In spontaneously breathing, decerebrate cats, extracellular recordings in the intermediate region of the ambiguus complex have been used to characterize the activity of inspiratory laryngeal motoneurones (ILMNs) during mechanical stimulation of tracheal irritant receptors. Laryngeal resistance was measured using an isolated larynx in situ. The effect of tracheal stimulation was analysed successfully in twenty-seven neurones. Eleven were ILMNs and sixteen inspiration-related neurones. Inspiration-related neurones increased their phasic discharge frequency during tracheal stimulation while ILMNs fired tonically, during both the inspiratory and the expiratory efforts of the cough. The tonic discharge of ILMNs coincided with a decrease of laryngeal resistance.