5-HT(3) receptor expression in the mouse vestibular ganglion.
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.
['Takimoto|Yasumitsu|Y|', 'Ishida|Yusuke|Y|', 'Nakamura|Yukiko|Y|', 'Kamakura|Takefumi|T|', 'Yamada|Takahiro|T|', 'Kondo|Makoto|M|', 'Kitahara|Tadashi|T|', 'Uno|Atsuhiko|A|', 'Imai|Takao|T|', 'Horii|Arata|A|', 'Okazaki|Suzuyo|S|', 'Nishiike|Suetaka|S|', 'Inohara|Hidenori|H|', 'Shimada|Shoichi|S|']
D000818:Animals D002118:Calcium D048429:Cell Size D002478:Cells, Cultured D017950:Ganglia, Sensory D017404:In Situ Hybridization, Fluorescence D008297:Male D008564:Membrane Potentials D051379:Mice D008810:Mice, Inbred C57BL D018345:Mice, Knockout D009474:Neurons D061848:Optical Imaging D010880:Piperidines D012333:RNA, Messenger D060888:Real-Time Polymerase Chain Reaction D044406:Receptors, Serotonin, 5-HT3 D058827:Serotonin 5-HT3 Receptor Agonists D013136:Spiral Ganglion
Inner ear In situ hybridization 5-HT Cochlea HTR3 Spiral ganglion