# Network modulators of auditory thalamocortical feedback inhibition

> **NIH NIH R21** · SOUTHERN ILLINOIS UNIVERSITY SCH OF MED · 2021 · $147,500

## Abstract

PROJECT SUMMARY/ABSTRACT
 Accurate coding and filtering of auditory information depends on the auditory thalamocortical circuit,
dysfunction of which is linked to tinnitus and Autism Spectrum Disorder (ASD). Within this circuit, the thalamic
reticular nucleus influences auditory thalamocortical neuron coding and activity to determine parameters of
attention and stimulus selection, but an understanding of this circuit is incomplete. Clearly, thalamic and cortical
afferents modulate the thalamic reticular nucleus, but other extrathalamocortical brain regions are also involved
in shaping the sensory filtering properties of the TRN. We hypothesize that brain regions which integrate multi-
modal sensory information to form internal predictions or determine emotional state are important for ‘tuning’ the
filtering properties of TRN neurons through modulation of TRN activity, auditory coding, and sensory selection
behaviors. Preliminary data indicate cerebellar output nuclei (sensorimotor predictions) and amygdala (emotion)
directly project to the thalamic reticular nucleus – a brain region that inhibits sensory thalamic neurons to
modulate stimulus coding, selection, and attention. This direct connection between cerebellum and thalamic
reticular nucleus may be an important conduit for the relay of multi-modal sensory information and related
predictions about surrounding events in time and space (e.g. changes in multiple acoustic stimuli sources,
background noise, etc.). Likewise, a direct projection from the amygdala to the thalamic reticular nucleus may
provide emotional context regulating selection of and attention to specific stimuli (e.g. heightened perception in
stressful environments). While anatomical evidence for these connections is clear, the function of cerebellar and
amygdala projections to thalamic reticular nucleus, cell type-specific circuitry, and subsequent influence on
auditory thalamic neurons is widely unknown. To address this knowledge gap and develop a comprehensive
model of this circuitry, we will perform whole cell recordings and immunohistochemistry/in situ hybridization on
neurons in the thalamic reticular nucleus (Aim 1), cerebellar nuclei, and amygdala (Aim 2) that will identify the
function of these pathways at a cellular level. Using an optogenetic approach, we will assess the neurotransmitter
released by each projection (Aim 1) and the functional and molecular identity of neurons forming this projection
in cerebellar nuclei and amygdala (Aim 2). These data will provide a foundation for identifying the functional
impact of cerebellar and/or amygdala projections to the thalamic reticular nucleus regarding dynamics of this
network, influence auditory processing in the thalamus, and involvement of these projections in stimulus
selection and attention.

## Key facts

- **NIH application ID:** 10227956
- **Project number:** 5R21DC018365-02
- **Recipient organization:** SOUTHERN ILLINOIS UNIVERSITY SCH OF MED
- **Principal Investigator:** Ben D Richardson
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $147,500
- **Award type:** 5
- **Project period:** 2020-08-03 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10227956

## Citation

> US National Institutes of Health, RePORTER application 10227956, Network modulators of auditory thalamocortical feedback inhibition (5R21DC018365-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10227956. Licensed CC0.

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