5-HT(3) receptor expression in the mouse vestibular ganglion.

Abstract

The 5-hydroxytryptamine type 3 (5-HT3) receptor is a ligand-gated ion channel and a member of the Cys-loop family of receptors. Previous studies have shown 5-HT3 receptor expression in various neural cells of the central and peripheral nervous systems. Although the function and distribution of the 5-HT3 receptor has been well established, its role in the inner ear is still poorly understood. Moreover, no study has yet determined its localization and function in the peripheral vestibular nervous system. In the present study, we reveal mRNA expression of both 5-HT3A and 5-HT3B receptor subunits in the mouse vestibular ganglion (VG) by RT-PCR and in situ hybridization (ISH). We also show by ISH that 5-HT3 receptor mRNA is only expressed in the VG (superior and inferior division) in the peripheral vestibular nervous system. Moreover, we performed Ca(2+) imaging to determine whether functional 5-HT3 receptors are present in the mouse VG, using a selective 5-HT3 receptor agonist, SR57227A. In wild mice, 32% of VG neurons responded to the agonist, whereas there was no response in 5-HT3A receptor knockout mice. These results indicate that VG cells express functional 5-HT3 receptor channels and might play a modulatory role in the peripheral vestibular nervous system.

• Authors: Yasumitsu Takimoto, Yusuke Ishida, Yukiko Nakamura, Takefumi Kamakura, Takahiro Yamada, Makoto Kondo, Tadashi Kitahara, Atsuhiko Uno, Takao Imai, Arata Horii, Suzuyo Okazaki, Suetaka Nishiike, Hidenori Inohara, Shoichi Shimada
• Journal: Brain research (Brain Res) Vol. 1557 Pg. 74-82 (Apr 04 2014) ISSN: 1872-6240 [Electronic] Netherlands
• PMID: 24530269 (Publication Type: Journal Article)
• Copyright: Copyright © 2014 Elsevier B.V. All rights reserved.

Chemical References

• Piperidines
• RNA, Messenger
• Receptors, Serotonin, 5-HT3
• Serotonin 5-HT3 Receptor Agonists
• 4-amino-1-(6-chloro-2-pyridyl)piperidine hydrochloride
• Calcium

Topics

• Animals
• Calcium (metabolism)
• Cell Size
• Cells, Cultured
• Ganglia, Sensory (drug effects, metabolism)
• In Situ Hybridization, Fluorescence
• Male
• Membrane Potentials (drug effects)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Neurons (drug effects, metabolism)
• Optical Imaging
• Piperidines (pharmacology)
• RNA, Messenger (genetics, metabolism)
• Real-Time Polymerase Chain Reaction
• Receptors, Serotonin, 5-HT3 (genetics, metabolism)
• Serotonin 5-HT3 Receptor Agonists (pharmacology)
• Spiral Ganglion (drug effects, metabolism)