# MECHANISMS OF AGE-RELATED AUDITORY SENSORY DEFICITS

> **NIH NIH R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 1992 · $317,689

## Abstract

Hearing loss related to aging (presbyacusis) is one of the major disorders
affecting the elderly, yet we know very little about what causes the
changes that occur in the auditory system and how these relate to hearing
loss.  Is human presbyacusis simply an aging of auditory structures, is it
aging plus the summing of a lifetime of ototraumatic insults from noise,
chemicals (drugs), and disease or are other factors such as changes in
blood flow, increased free radical formation, genetically programmed
neuronal cell death, increased susceptibility to noise or chemical damage
or even diet significant?  Is human presbyacusis not the result of "pure
aging" of auditory structures and this the reason no adequate animal model
has been found?  We have established a collaborative effort between the
laboratories of anatomy, biochemistry and physiology of the Kresge Hearing
Research Institute to elucidate mechanisms involved in the development of
auditory sensory deficits in aging.  We will perform morphological and
neurochemical assessments in guinea pig and rat to test the following
hypotheses:  1) That age-related loss of spiral ganglion cells and changes
in inhibitory and excitatory circuitry in auditory brainstem and cochlea
occur independently of changes in organ of Corti, 2) That there are age-
related changes in cochlear blood flow, cochlear vessels and cochlear
vascular reactivity, 3) That changes in the sensitivity of cochlear hair
cells to ototraumatic insults occur with aging, 4) That free radical
accumulation induces changes in lipid peroxidation, membrane lipid domains,
membrane fluidity and function in aging, and 5) That increased fat and/or
cholesterol diet influences the age-related changes listed above.
Physiological assessments of auditory function will be performed for
correlation with these parameters.

This will provide us with information that will help us not only to better
understand the origins and development of hearing loss in the elderly, but,
to develop more effective methods of its treatment and prevention.

## Key facts

- **NIH application ID:** 3120682
- **Project number:** 5R01AG008885-03
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **SAM.gov UEI:** GNJ7BBP73WE9
- **Principal Investigator:** RICHARD A ALTSCHULER
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $317,689
- **Award type:** 5
- **Project period:** 1990-03-01 → 1995-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3120682

## Citation

> US National Institutes of Health, RePORTER application 3120682, MECHANISMS OF AGE-RELATED AUDITORY SENSORY DEFICITS (5R01AG008885-03). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3120682. Licensed CC0.

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