# Evaluation of a structure-function model for auditory consequences of impact acceleration brain injury and protection via the olivocochlear system

> **NIH NIH F32** · JOHNS HOPKINS UNIVERSITY · 2022 · $67,582

## Abstract

Project Summary
Auditory dysfunction can occur acutely after brain injuries and continues to change over time after injury. Brain
injuries lead to heterogeneity of structural and functional consequences even when the injury is performed
identically in a controlled laboratory setting. The effects of brain injuries on auditory system function have not
been systematically examined longitudinally in animal models to understand the factors contributing to
heterogeneity. The goal of this proposal is to investigate the heterogeneity in auditory functional outcomes after
impact acceleration TBI (IA-TBI) or sham conditions and look for underlying structural correlates to injury in the
ear and brainstem. In Aim 1, we will evaluate auditory function and corresponding patterns of neurodegeneration
in the cochlea and auditory brainstem caused by impact-acceleration TBI up to 90 days after injury. Damage to
afferent and efferent neurons in the cochlea and cochlear nucleus will be quantified. The role of the olivocochlear
efferent system as a mechanism of protective effects of simultaneous noise exposure during IA-TBI, such as
what might occur during a car crash, will be investigated in Aim 2. Subjects with genetically weakened
olivocochlear feedback will be exposed to an IA- TBI in quiet or noise or sham conditions and evaluated for
decreased protection from the auditory consequences of injury. Immunohistochemistry and confocal microscopy
will be used to quantify damage to hair cells, afferent, and efferent synapses. Immunohistochemistry staining
and acetylcholinesterase labeling and light microscopy will be used to quantify changes in the number of axons
in auditory regions in the brainstem using stereological measurements. The results of the proposed experiments
will provide insight into the underlying causes of heterogeneity in the structural and functional consequences of
TBI and the olivocochlear system as a potential mechanism for protection to create a more ecologically valid
model for human brain trauma. The applicant will receive training in confocal and light microscopy, quantitative
anatomical analysis, the olivocochlear system, auditory brainstem anatomy, and neurotrauma. Additional
professional development training activities and attendance at local and national scientific conferences are
planned. The sponsor team includes investigators with the expertise and commitment to enhance the applicant’s
training experience.

## Key facts

- **NIH application ID:** 10605573
- **Project number:** 1F32DC020346-01A1
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Kali Burke
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $67,582
- **Award type:** 1
- **Project period:** 2022-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10605573

## Citation

> US National Institutes of Health, RePORTER application 10605573, Evaluation of a structure-function model for auditory consequences of impact acceleration brain injury and protection via the olivocochlear system (1F32DC020346-01A1). Retrieved via AI Analytics 2026-07-08 from https://api.ai-analytics.org/grant/nih/10605573. Licensed CC0.

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