Serotonin 2B receptor: upregulated with age and hearing loss in mouse auditory system

Neurobiol Aging. 2007 Jul;28(7):1112-23. doi: 10.1016/j.neurobiolaging.2006.05.021. Epub 2006 Jul 5.

Abstract

Serotonin (5-HT) is a monoamine neurotransmitter. Serotonin may modulate afferent fiber discharges in the cochlea, inferior colliculus (IC) and auditory cortex. Specific functions of serotonin are exerted upon its interaction with specific receptors; one of those receptors is the serotonin 2B receptor. The aim of this study was to investigate the differences in gene expression of serotonin 2B receptors with age in cochlea and IC, and the possible correlation between gene expression and functional hearing measurements in CBA/CaJ mice. Immunohistochemical examinations of protein expression of IC in mice of different age groups were also performed. Gene expression results showed that serotonin 2B receptor gene was upregulated with age in both cochlea and IC. A significant correlation between gene expression and functional hearing results was established. Immunohistochemical protein expression studies of IC showed more serotonin 2B receptor cells in old mice relative to young adult mice, particularly in the external nucleus. We conclude that serotonin 2B receptors may play a role in the pathogenesis of age-related hearing loss.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Acoustic Stimulation / methods
  • Aging*
  • Analysis of Variance
  • Animals
  • Auditory Pathways / physiopathology*
  • Auditory Threshold / physiology
  • Dose-Response Relationship, Radiation
  • Evoked Potentials, Auditory, Brain Stem / physiology
  • Gene Expression Profiling
  • Hearing Loss / pathology*
  • Mice
  • Mice, Inbred CBA
  • Models, Animal
  • Oligonucleotide Array Sequence Analysis / methods
  • Otoacoustic Emissions, Spontaneous / physiology
  • RNA, Messenger / biosynthesis
  • Receptor, Serotonin, 5-HT2B / genetics
  • Receptor, Serotonin, 5-HT2B / metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Up-Regulation / physiology*

Substances

  • RNA, Messenger
  • Receptor, Serotonin, 5-HT2B