Fos expression in the brainstem nuclei evoked by nasal air-jet stimulation in rats.

摘要

BACKGROUND: Noxious stimulation of the nasal mucosa may induce protective reflexes in the upper airway in rats. Previously, we have reported that nasal air-jet stimulation increases the activities of the laryngeal muscles in decerebrate cats; however, the neuronal mechanism of this phenomenon still is not clarified. METHODS: After the application of nasal air-jet stimulation for 2 hours, we investigated the distribution of Fos-positive cells (FPCs) throughout the medulla compared with sham-operated rats using Fos immunoreactivity. RESULTS: FPCs in the spinal trigeminal nucleus, the parvocellular reticular nucleus, and the nucleus of the solitary tract were more frequent than the sham-operated rats. CONCLUSION: These results suggest that the afferents induced by air-jet stimulation were conveyed to these FPCs and that some of these cells might participate in the augmentation of laryngeal muscle activities during nasal air-jet stimulation.