ASYMMETRY IN REFLEX RESPONSES OF NASAL MUSCLES IN ANESTHETIZED GUINEA-PIGS

Nasal reflexes elicited by mechanical or electrical stimulation of nas al afferents were studied in anesthetized guinea pigs. Probing the nas al cavity of one side evoked a greater activation of the contralateral than the ipsilateral nasal muscles and, occasionally, sneezing. Simil arly, electrical stimulation of the ethmoidal nerve often caused sneez ing, with a greater activation of the nasal muscles and a greater incr ease in resistance on the contralateral side. Asymmetrical activation of the nasal muscles in response to mechanical stimuli induces asymmet rical airflows, especially during sneezing, between the two sides of t he nasal cavity. Most of the expired air is forcibly blown out through the ipsilateral nostril, thus improving the elimination of irritants from the nose.