# Physiology of Vestibular Compensation

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2022 · $516,226

## Abstract

Project Summary
 This research program is motivated by two goals. First, we seek to understand the neural mechanisms by
which the brain adapts to changes in vestibular (inner ear balance) input. Second, we seek to advance
development of a vestibular prosthesis/implant, a highly innovative treatment approach with potential to
improve quality of life for individuals disabled by disequilibrium and unsteady vision after loss of vestibular
sensation. In the United States alone, about 150,000 adults suffer disabling vertigo and unsteadiness each
year due to acute unilateral loss of vestibular function, while about 65,000 suffer chronic imbalance and
unsteady vision typical of severe bilateral sensory loss that fails to resolve despite existing treatments.
 Sudden, permanent loss of vestibular nerve input causes disequilibrium, visual blurring due to disruption of
the vestibulo-ocular reflex (VOR), and postural instability due to disruption of vestibulo-spinal reflexes. These
symptoms are usually followed by impressive but incomplete recovery. During the previous funding period, we
made excellent progress toward defining the dynamics of compensation in pathways that mediate these vital
reflexes. In addition, we established how these pathways respond acutely to activation of a multichannel
vestibular prosthesis (MVP). In the proposed research program, we will build upon this solid foundation of
progress through 3 synergistic aims. Experiments addressing Aim 1 will determine how central vestibular
neurons adapt to the onset of constant prosthetic stimulation, to subsequent cessation of stimulation, and to
motion-modulated stimulation. We predict that adaptation predominantly involves changes in one of two
parallel paths, and that reduction of afferent discharge synchrony and/or addition of congruent extra-vestibular
self-motion cues will further improve responses. Aim 2 experiments will examine how central neurons process
prosthetic vestibular input during natural behaviors such as vergence, active gaze shifts and VOR suppression,
which all require context-specific integration of neuronal signals encoding non-vestibular senses and efferent
commands. These experiments will extend our investigation beyond reflex pathways and provide both systems
and neuronal-level insight into how the central nervous system (CNS) optimizes performance during complex
behaviors typical of daily life. Experiments addressing Aim 3 will characterize central vestibular neuron
adaptation to natural and prosthetic stimulation during a novel training paradigm designed to reduce VOR
asymmetry. Combined, these studies in alert nonhuman primates will enhance understanding of how the CNS
adapts to changes in vestibular input; advance development of a potentially revolutionary treatment for loss of
inner ear function; and clarify how neuronal mechanisms that underlie learning at a cellular level can be
leveraged to optimize recovery of individuals disabled by loss of vestibular sensation...

## Key facts

- **NIH application ID:** 10436209
- **Project number:** 5R01DC002390-25
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Kathleen E Cullen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $516,226
- **Award type:** 5
- **Project period:** 1995-09-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10436209

## Citation

> US National Institutes of Health, RePORTER application 10436209, Physiology of Vestibular Compensation (5R01DC002390-25). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10436209. Licensed CC0.

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