# Dendritic Integration and Synaptic Plasticity in the MSO

> **NIH NIH R01** · UNIVERSITY OF TEXAS AT AUSTIN · 2020 · $430,270

## Abstract

Project Summary
 Humans and other mammals use the temporal fine structure in sounds to identify and help
localize auditory objects in three-dimensional space. The broad goal of this research is both to
understand how sound localization cues are processed in the brain as well as to understand how
neurons in the underlying circuitry acquire the appropriate biophysical properties during development.
This proposal focuses on the medial superior olive (MSO), the first and critical stage for processing
interaural time differences (ITDs) from the two ears, cues that are used for horizontal sound localization
as well as for understanding speech patterns in noisy environments. ITDs are computed in the MSO via
the process of coincidence detection, in which the simultaneous arrival of excitatory inputs from the two
ears is detected and conveyed through action potential firing with a time resolution of a few tens of
microseconds.
 The neurons of the MSO have historically been assumed to be functionally and morphologically
homogeneous. However, our preliminary data refutes this simplistic view of the MSO: we hypothesize
instead that variation in dendritic morphology and electrical properties critically shapes the location of
spatial receptive fields, and that these differences are in part influenced after hearing onset by the level
and pattern of neural activity. We will address these questions by combining paired dendritic and somatic
patch recordings, compartmental modeling, patterned LED illumination of light-sensitive channel
blockers, and hearing manipulations. Aim 1 will address the functional significance of the newly
discovered tonotopic diversity in electophysiological properties of MSO neurons both in vitro using patch-
clamp recordings. Aim 2 will extend these analyses to understand how the functional diversity in MSO
neurons is conferred by differences in the expression levels and properties of voltage-gated channels in
the axon initial segment. Aim 3 will explore how the diversity of dendritic structure itself shapes the
temporal requirements for optimal detection of binaural coincidence.
 The information from these experiments will increase our understanding of the mechanisms
underlying spatial hearing in mammals, as well as the developmental processes that control the
formation of a critical circuit component in the MSO. As binaural hearing is important for speech
perception and language acquisition in children, a mechanistic understanding of binaural circuit function
and development may ultimately inform clinical strategies for addressing hearing impairments.

## Key facts

- **NIH application ID:** 9853005
- **Project number:** 5R01DC006877-15
- **Recipient organization:** UNIVERSITY OF TEXAS AT AUSTIN
- **Principal Investigator:** Nace L Golding
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $430,270
- **Award type:** 5
- **Project period:** 2004-07-01 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9853005

## Citation

> US National Institutes of Health, RePORTER application 9853005, Dendritic Integration and Synaptic Plasticity in the MSO (5R01DC006877-15). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9853005. Licensed CC0.

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