# Cortical circuits for temporal integration of multi-frequency sounds

> **NIH NIH R01** · UNIV OF NORTH CAROLINA CHAPEL HILL · 2020 · $323,077

## Abstract

PROJECT SUMMARY
In our daily life, even in the face of multiple sound sources, our brain binds together frequency components
that belong to the same source and recognizes individual sound objects. In humans, grouping of spectral
components into single sound perception relies on the precise synchrony (< 30-ms window) of their onset
timings, and this grouping plays a critical role in our perception of language. Despite the importance of this
“sensory feature binding”, we still know little regarding the neuronal circuit mechanisms underlying how our
brain integrates spectrally and temporally distributed sound inputs. To address this gap in knowledge, this
project will define neuronal circuits underlying the binding of harmonic sounds using mouse auditory cortex as
a model system. Mouse auditory cortex consists of five areas that are interconnected to form hierarchical
processing streams. Our preliminary data indicates that a higher auditory cortical area, A2, selectively
represents multi-frequency sounds with coincident onset timings. We hypothesize that inhibitory circuits in A2
gate the integration of tones in a synchrony-dependent manner, and this gating gives mice an ability to detect
harmonic sounds. Our goal is to examine this hypothesis by taking advantage of cutting-edge two-photon
calcium imaging and in vivo whole-cell recording techniques that are available in mice. To achieve our goal,
this project aims to (1) Determine the distinct spectro-temporal integration across auditory areas (macroscopic
and cellular-level calcium imaging), (2) Dissect the circuit mechanisms underlying spectro-temporal integration
(in vivo whole-cell recordings), and (3) Determine the perceptual roles of higher auditory cortices in processing
harmonics (optogenetics during behaviors). Findings in the simple mouse cortex should provide a first step
towards the ultimate understanding of the “feature binding” circuits that enable verbal communication, and how
they fail in diseased brains.

## Key facts

- **NIH application ID:** 9969366
- **Project number:** 5R01DC017516-02
- **Recipient organization:** UNIV OF NORTH CAROLINA CHAPEL HILL
- **Principal Investigator:** Hiroyuki Kato
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $323,077
- **Award type:** 5
- **Project period:** 2019-07-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9969366

## Citation

> US National Institutes of Health, RePORTER application 9969366, Cortical circuits for temporal integration of multi-frequency sounds (5R01DC017516-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9969366. Licensed CC0.

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