title: SCN2B in the Rat Trigeminal Ganglion and Trigeminal Sensory Nuclei.
abstract: The beta-2 subunit of the mammalian brain voltage-gated sodium channel (SCN2B) was examined in the rat trigeminal ganglion (TG) and trigeminal sensory nuclei. In the TG, 42.6 % of sensory neurons were immunoreactive (IR) for SCN2B. These neurons had various cell body sizes. In facial skins and oral mucosae, corpuscular nerve endings contained SCN2B-immunoreactivity. SCN2B-IR nerve fibers formed nerve plexuses beneath taste buds in the tongue and incisive papilla. However, SCN2B-IR free nerve endings were rare in cutaneous and mucosal epithelia. Tooth pulps, muscle spindles and major salivary glands were also innervated by SCN2B-IR nerve fibers. A double immunofluorescence method revealed that about 40 % of SCN2B-IR neurons exhibited calcitonin gene-related peptide (CGRP)-immunoreactivity. However, distributions of SCN2B- and CGRP-IR nerve fibers were mostly different in facial, oral and cranial structures. By retrograde tracing method, 60.4 and 85.3 % of TG neurons innervating the facial skin and tooth pulp, respectively, showed SCN2B-immunoreactivity. CGRP-immunoreactivity was co-localized by about 40 % of SCN2B-IR cutaneous and tooth pulp TG neurons. In trigeminal sensory nuclei of the brainstem, SCN2B-IR neuronal cell bodies were common in deep laminae of the subnucleus caudalis, and the subnuclei interpolaris and oralis. In the mesencephalic trigeminal tract nucleus, primary sensory neurons also exhibited SCN2B-immunoreactivity. In other regions of trigeminal sensory nuclei, SCN2B-IR cells were very infrequent. SCN2B-IR neuropil was detected in deep laminae of the subnucleus caudalis as well as in the subnuclei interpolaris, oralis and principalis. These findings suggest that SCN2B is expressed by various types of sensory neurons in the TG. There appears to be SCN2B-containing pathway in the TG and trigeminal sensory nuclei.
authors: Division of Oral Diagnosis, Graduate School of Dentistry, Tohoku University, Sendai, 980-8575, Japan.
authors: Yusuke
authors: Y
authors: Shimada
authors: Division of Oral and Craniofacial Anatomy, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Sendai, 980-8575, Japan.
authors: Tadasu
authors: T
authors: Sato
authors: Division of Operative Dentistry, Graduate School of Dentistry, Tohoku University, Sendai, 980-8575, Japan.
authors: Takehiro
authors: T
authors: Yajima
authors: Division of Dental Anesthesiology and Pain Management, Graduate School of Dentistry, Tohoku University, Sendai, 980-8575, Japan.
authors: Masatoshi
authors: M
authors: Fujita
authors: Division of Oral Diagnosis, Graduate School of Dentistry, Tohoku University, Sendai, 980-8575, Japan.
authors: Naoya
authors: N
authors: Hashimoto
authors: Division of Oral Diagnosis, Graduate School of Dentistry, Tohoku University, Sendai, 980-8575, Japan.
authors: Noriaki
authors: N
authors: Shoji
authors: Division of Oral Diagnosis, Graduate School of Dentistry, Tohoku University, Sendai, 980-8575, Japan.
authors: Takashi
authors: T
authors: Sasano
authors: Division of Oral and Craniofacial Anatomy, Graduate School of Dentistry, Tohoku University, 4-1 Seiryo-machi, Sendai, 980-8575, Japan. hiroichi@anat.dent.tohoku.ac.jp.
authors: Hiroyuki
authors: H
authors: Ichikawa
mesh_terms: D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D005145:Face / Q000294:innervation; D008297:Male; D009055:Mouth / Q000294:innervation / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D011984:Sensory Receptor Cells / Q000378:metabolism; D012886:Skull / Q000294:innervation / Q000378:metabolism; D012668:Trigeminal Ganglion / Q000378:metabolism*; D014278:Trigeminal Nuclei / Q000378:metabolism*; D062548:Voltage-Gated Sodium Channel beta-2 Subunit / Q000096:biosynthesis*
chemical_list: C000614272:SCN2B protein, rat; D062548:Voltage-Gated Sodium Channel beta-2 Subunit; D015740:Calcitonin Gene-Related Peptide
keywords: Facial skin; SCN2B; Tooth pulp; Trigeminal ganglion; Trigeminal sensory nucleus; Vibrissa