# Spontaneous activity in the developing auditory system

> **NIH DC R01** · JOHNS HOPKINS UNIVERSITY · 2026 · $417,875

## Abstract

Project Summary
Neurons in the developing auditory system exhibit spontaneous activity prior to the onset of sensory
experience. This activity is initiated within the cochlea when non-sensory inner supporting cells release ATP,
triggering a cascade of events that ultimately induces trains of action potentials in spiral ganglion neurons
(SGNs). Our prior studies revealed that this spatially restricted release of ATP triggers correlated firing of
groups of SGNs that will later encode similar frequencies of sound, and showed that this burst firing
propagates through the CNS to set the gain of auditory circuits, refine the frequency tuning of auditory
neurons, and establish sound processing domains within the inferior colliculus and auditory cortex. Despite its
role in maturation of the auditory system, the mechanisms that initiate this activity and its relationship to the
dramatic structural transformation that occurs in the cochlea during this same time period remain poorly
understood. We recently discovered a previously undescribed form of spontaneous activity in the developing
cochlea involving local kinase activation within inner supporting cells (ISCs) – termed Spatiotemporally
Restricted ERK Signaling (“SpaRKS”) – that is coincident with ATP induced activity. Here, we will leverage
newly developed kinase reporter mice, in vivo genetic manipulations, and time lapse fluorescence imaging in
ex vivo cochlear explants and in vivo central auditory centers to explore the mechanisms responsible for this
signaling and its relationship to both thyroid hormone-induced maturation processes and ATP driven
spontaneous activity. We will test the explicit hypothesis that thyroid hormone induced apoptosis of ISCs
triggers both growth factor and ATP release to control the pace of cellular regression and initiate burst firing
during this critical phase of development. Aim 1 will use pharmacological and genetic manipulations to define
the mechanisms responsible for local ERK activit

## Key facts

- **NIH application ID:** 11367570
- **Project number:** 2R01DC008860-14
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** DWIGHT E BERGLES
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** DC
- **Fiscal year:** 2026
- **Award amount:** $417,875
- **Award type:** 2
- **Project period:** 2007-12-01T00:00:00 → 2031-03-31T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11367570

## Citation

> US National Institutes of Health, RePORTER application 11367570, Spontaneous activity in the developing auditory system (2R01DC008860-14). Retrieved via AI Analytics 2026-06-24 from https://api.ai-analytics.org/grant/nih/11367570. Licensed CC0.

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