Effects of ethmoidal nerve stimulation on respiration-related neurones in the dorsal medulla of the cat

Stimulation of the nasal mucosa produces a number of respiratory reflexes the afferent limb of which is provided by the ethmoidal nerve, a branch of the trigeminal nerve. In the cat this nerve terminates within the trigeminal nucleus. It has no direct projection to brainstem respiratory centres. This study examines the response of respiratory-related neurones in the nucleus of the solitary tract (NTS) to ethmoidal stimulation. It demonstrates that these neurones show both excitatory and inhibitory responses to ethmoidal stimulation. Thus, the NTS appears to be involved in respiratory reflexes initiated by stimulation of the nasal mucosa.