# Learning Related Plasticity in Mammalian Sound Localization Circuits

> **NIH DC R01** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2026 · $613,304

## Abstract

Project Summary / Abstract
Binaural cues enable sound localization, which supports active listening by spatially segregating competing
sound streams. Consequently monaural hearing loss impairs sound localization and listening comprehension,
despite normal function in the spared ear. Encouragingly, humans and animals with monaural hearing loss can
re-learn sound localization if provided with appropriate training, though success is variable. Identifying
actionable targets to improve outcomes could thus benefit hearing health, but progress is limited by our
meager understanding of central plasticity mechanisms that support learned sound localization. Interestingly,
descending (“corticofugal”) projections from auditory cortex to subcortical auditory centers are required for
monaurally deprived animals to relearn sound localization. However, their precise role in this process is poorly
understood. This renewal addresses this knowledge gap by building upon our recent progress studying the role
of corticofugal projections in discriminative learning. In tandem with unpublished data, our results suggest a
new working hypothesis: Auditory corticofugal neurons and/or their subcortical targets are plasticity loci to
establish learned, conjunctive representations of sounds and their behaviorally relevant consequences. Such
“mixed selectivity” is powerful: It enables linking “where” and “what” information across time, thereby
generating context-specific representations of auditory space that could support learned sound localization. To
test this hypothesis, we have developed a new sound localization task that head-fixed mice learn with binaural
cues, and can re-learn following monaural conductive hearing loss. We will combine this approach with
longitudinal Ca2+ imaging and optogenetics to record and manipulate activity in corticofugal neurons and their
subcortical targets. The results will provide new insights into central auditory plasticity during learned sound
localization, w

## Key facts

- **NIH application ID:** 11243085
- **Project number:** 2R01DC019090-06A1
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** Pierre F Apostolides
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** DC
- **Fiscal year:** 2026
- **Award amount:** $613,304
- **Award type:** 2
- **Project period:** 2021-01-01T00:00:00 → 2031-02-28T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11243085

## Citation

> US National Institutes of Health, RePORTER application 11243085, Learning Related Plasticity in Mammalian Sound Localization Circuits (2R01DC019090-06A1). Retrieved via AI Analytics 2026-07-03 from https://api.ai-analytics.org/grant/nih/11243085. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*