# Coding of auditory space in the mouse superior colliculus

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA SANTA CRUZ · 2023 · $88,287

## Abstract

The Superior Colliculus (SC) plays an essential role in processing auditory information to assess saliency
and promote action; however, the underlying cell types and circuitry used to encode sound source locations
remain largely unknown. Work done in primates and ferrets has shown that the receptive fields (RFs) of
neurons in the deep SC (dSC) are organized in a 2-dimensional map of auditory space. This has recently been
shown to also be true in the mouse, an organism that already has molecular and genetic tools available that
will allow us to dissect circuitry to understand how this map forms.
 The overall objective of this application is to determine the functional properties of auditory neurons in the
mouse SC, determine how these properties are encoded, and determine which brainstem and cortical inputs
influence these properties. Our central hypothesis is that a combination of interaural level differences (ILD) and
two sets of spectral cues are used to compute a 2-dimensional map of sound space; these are inherited from
different brainstem regions and are modulated by the cortex. The goal of Specific Aim 1 is to test the
hypothesis that the 2-dimensional map of sound space is encoded by the SC using a combination of ILDs and
two sets of spectral cue patterns. To achieve this we will stimulate awake head-fixed mice, allowed to freely
run on a treadmill, with spatially/temporally/spectrally restricted auditory stimuli, then simultaneously record SC
neuronal response properties of thousands of auditory responsive neurons. Data analysis will determine the
spatiotemporal and spectral/temporal receptive fields (RFs) of auditory neurons, their locations within the SC,
the dependence of their RFs on ILDs and specific frequency combinations, and if these properties are
modulated by locomotion. Experiments proposed in Specific Aim 2 will test the hypothesis that the SC
computes sound location by combining inputs from different brainstem nuclei. We will record the response
properties of the brachium of the inferior colliculus, the external nucleus of the IC, and the nucleus of the lateral
lemniscus to auditory stimuli, and compare their RF properties to those in the SC. We will also use
optogenetics to selectively excite or inhibit neurons that project from these areas to the SC in order to identify
their specific contributions to the SC responses. In Specific Aim 3 we test the hypothesis that the direct
projection from the auditory cortex to the SC is used to modulate the response properties of dSC neurons by
measuring the response properties of auditory SC neurons both in mice that lack a cortico-collicular projection,
and in those that have their auditory cortico-collicular projection silenced via optogenetics.
The proposed research plan is significant because the results will establish the mouse SC as a model to study
auditory spatial mapping and eventually auditory/visual spatial integration. Our findings will also lead to a better
understanding of...

## Key facts

- **NIH application ID:** 10840631
- **Project number:** 3R01DC018580-03S1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA SANTA CRUZ
- **Principal Investigator:** DAVID A FELDHEIM
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $88,287
- **Award type:** 3
- **Project period:** 2021-03-01 → 2026-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10840631

## Citation

> US National Institutes of Health, RePORTER application 10840631, Coding of auditory space in the mouse superior colliculus (3R01DC018580-03S1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10840631. Licensed CC0.

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