Calcitonin gene-related peptide immunoreactive neurons innervating the soft palate, the root of tongue, and the pharynx in the superior glossopharyngeal ganglion of the rat.
We have examined whether calcitonin gene-related peptide immunoreactive (CGRP-ir) neurons in the glossopharyngeal ganglia innervate the soft palate, the root of tongue, and the pharynx of the rat. Immunohistochemical observations revealed that numerous CGRP-ir neurons are located in the superior glossopharyngeal ganglion located ventrolateral to the medulla oblongata in the cranial cavity, and that CGRP-ir neurons are also located in the inferior glossopharyngeal ganglion at the jugular foramen. When Fluorogold was injected into the soft palate, the root of tongue, or the pharyngeal constrictor muscles, many retrogradely Fluorogold-labeled neurons were found in the superior glossopharyngeal ganglion and the nodose ganglion, and several Fluorogold-labeled neurons were found in the inferior glossopharyngeal ganglion. Double labeling with immunohistochemistry for CGRP and Fluorogold showed that in every case of injections of Fluorogold into the soft palate, the root of tongue, or the pharynx, about 30% of the Fluorogold-labeled neurons in the superior glossopharyngeal ganglion expressed CGRP-like immunoreactivity, while no double-labeled neurons were found in the inferior glossopharyngeal ganglion or the nodose ganglion. These results indicate that nociceptive sensory information from the soft palate, the root of tongue, and the pharynx might be conveyed by the neurons in the superior glossopharyngeal ganglion to the nucleus tractus solitarii.
Hayakawa
Tetsu
T
Department of Anatomy, Hyogo College of Medicine, Mukogawa, Nishinomiya, Hyogo 663-8501, Japan. tetsu@hyo-med.ac.jp <tetsu@hyo-med.ac.jp>
Kuwahara
Sachi
S
Maeda
Seishi
S
Tanaka
Koichi
K
Seki
Makoto
M
D000344:Afferent Pathways / Q000166:cytology / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D017950:Ganglia, Sensory / Q000166:cytology / Q000378:metabolism*; D005930:Glossopharyngeal Nerve / Q000166:cytology / Q000378:metabolism*; D007150:Immunohistochemistry; D008297:Male; D009055:Mouth / Q000294:innervation*; D056325:Neuronal Tract-Tracers; D009619:Nociceptors / Q000166:cytology / Q000378:metabolism; D010146:Pain / Q000378:metabolism / Q000503:physiopathology; D010160:Palate, Soft / Q000294:innervation; D010614:Pharynx / Q000294:innervation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011984:Sensory Receptor Cells / Q000166:cytology / Q000378:metabolism*; D017552:Solitary Nucleus / Q000166:cytology / Q000378:metabolism; D013266:Stilbamidines; D014059:Tongue / Q000294:innervation
C049774:2-hydroxy-4,4'-diamidinostilbene, methanesulfonate salt; D015415:Biomarkers; D056325:Neuronal Tract-Tracers; D013266:Stilbamidines; D015740:Calcitonin Gene-Related Peptide