# Cortical mechanisms for contrast gain control in auditory perception in noise.

> **NIH NIH F31** · UNIVERSITY OF PENNSYLVANIA · 2024 · $48,974

## Abstract

PROJECT SUMMARY
Cortical mechanisms for contrast gain control in auditory perception in noise.
Everyday natural auditory environments are variable, ranging from quiet beaches to raging waterfalls. In order
to identify and robustly encode important sounds like speech from the background noise, the auditory system
needs to flexibly adapt to the current environment. One way the auditory system does this is by modifying neuron
response properties according to the statistics of the auditory environment. Neurons in the primary auditory
cortex (A1) adapt response function slope (gain) to account for changes in auditory variability (contrast). This
gain adaptation process is associated with corresponding changes in perceptual sensitivity. The mechanisms
driving this process are still unknown. The goal of this proposal is to identify the circuit mechanisms
responsible for contrast-dependent perceptual changes and neuronal gain adaptation in A1. In addition
to excitatory neurons, A1 comprises many types of inhibitory interneurons. Two subtypes, parvalbumin-positive
(PV) and somatostatin-positive (SST) interneurons, are capable of shaping the gain of their surrounding
excitatory neurons. We hypothesize that PV and SST neurons work together to differentially adapt neuron gain
to auditory contrast. We will first test this hypothesis by establishing whether PV and SST neurons are sensitive
to the environment’s contrast. Using electrophysiological recordings with optotagging, we will record PV and SST
neuron activity in mouse A1. Next, we will test whether SST and PV activity drives the perceptual sensitivity
changes associated with gain adaptation. By optogenetically perturbing PV and SST activity in A1 of mice
performing target-in-noise detection tasks with variable stimulus contrasts, we will quantify the relative
contributions of PV and SST neurons to perceptual sensitivity changes. Together, these results will characterize
the roles of inhibitory cortical circuits in adaptation to the current auditory environment, deepening our
understanding of effective auditory processing in noisy environments.

## Key facts

- **NIH application ID:** 11069780
- **Project number:** 1F31DC022507-01
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Omer Zeliger
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $48,974
- **Award type:** 1
- **Project period:** 2024-08-01 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11069780

## Citation

> US National Institutes of Health, RePORTER application 11069780, Cortical mechanisms for contrast gain control in auditory perception in noise. (1F31DC022507-01). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/11069780. Licensed CC0.

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