Degeneration of spiral ganglion (cochlear) neurons is one of the most commonly observed changes in the aging inner ear. In humans and some animal species, neuronal degeneration occurs in the absence of sensory hair cell loss. One factor contributing to neuronal presbyacusis may be changes in the production of trophic molecules derived from sensory hair cells, ganglionic supporting cells or the neurons themselves. Several neurotrophic factors are expressed in the inner ear and members of the neurotrophin gene family are known to be critical for development of cochlear and vestibular neurons. To test the hypothesis that changes in neurotrophins and/or their associated receptors contribute to the age- related loss of neurons, a series of complementary experiments will be conducted using gerbil and human inner ear tissue.
Aim 4. 1 addresses the temporal and spatial expression of neurotrophins and their associated receptors using the reverse transcription polymerase chain reaction and in situ hybridization.
Aim 4. 2 evaluates the production of neurotrophin- like proteins using immunohistochemistry, in vitro assays of inner ear tissues and enzyme-linked immunoabsorbant assays.
Aim 4. 3 examines whether the survival or outgrowth of neuronal processes from young and aging cochlear neurons is influenced by exogenously applied neurotrophins or other inner ear-derived factors. Together, the proposed experiments will offer new sights into the role of neurotrophins in the aging inner ear as well as information regarding the therapeutic potential of neurotrophic molecules in preventing age-related hearing loss.

Project Start
2000-07-01
Project End
2001-06-30
Budget Start
1998-10-01
Budget End
1999-09-30
Support Year
14
Fiscal Year
2000
Total Cost
$181,409
Indirect Cost
Name
Medical University of South Carolina
Department
Type
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Lewis, Morag A; Nolan, Lisa S; Cadge, Barbara A et al. (2018) Whole exome sequencing in adult-onset hearing loss reveals a high load of predicted pathogenic variants in known deafness-associated genes and identifies new candidate genes. BMC Med Genomics 11:77
Bologna, William J; Vaden Jr, Kenneth I; Ahlstrom, Jayne B et al. (2018) Age effects on perceptual organization of speech: Contributions of glimpsing, phonemic restoration, and speech segregation. J Acoust Soc Am 144:267
Panganiban, Clarisse H; Barth, Jeremy L; Darbelli, Lama et al. (2018) Noise-induced dysregulation of Quaking RNA binding proteins contributes to auditory nerve demyelination and hearing loss. J Neurosci :
Chiarello, Christine; Vaden Jr, Kenneth I; Eckert, Mark A (2018) Orthographic influence on spoken word identification: Behavioral and fMRI evidence. Neuropsychologia 111:103-111
Harris, Kelly C; Vaden Jr, Kenneth I; McClaskey, Carolyn M et al. (2018) Complementary metrics of human auditory nerve function derived from compound action potentials. J Neurophysiol 119:1019-1028
McRackan, Theodore R; Fabie, Joshua E; Burton, Jane A et al. (2018) Earphone and Aided Word Recognition Differences in Cochlear Implant Candidates. Otol Neurotol 39:e543-e549
Dubno, Judy R (2018) Beyond the audiogram: application of models of auditory fitness for duty to assess communication in the real world. Int J Audiol 57:321-322
McRackan, Theodore R; Clinkscales, William B; Ahlstrom, Jayne B et al. (2018) Factors associated with benefit of active middle ear implants compared to conventional hearing aids. Laryngoscope 128:2133-2138
Dias, James W; McClaskey, Carolyn M; Harris, Kelly C (2018) Time-Compressed Speech Identification Is Predicted by Auditory Neural Processing, Perceptuomotor Speed, and Executive Functioning in Younger and Older Listeners. J Assoc Res Otolaryngol :
Worley, Mitchell L; Schlosser, Rodney J; Soler, Zachary M et al. (2018) Age-related differences in olfactory cleft volume in adults: A computational volumetric study. Laryngoscope :

Showing the most recent 10 out of 135 publications