# The function of thalamic inhibition in auditory processing

> **NIH NIH F31** · UNIVERSITY OF PENNSYLVANIA · 2021 · $33,253

## Abstract

PROJECT SUMMARY
The function of thalamic inhibition in auditory processing.
 Interactions between inhibitory and excitatory neurons along the auditory pathway shape how acoustic
information is processed in the brain. The thalamic reticular nucleus (TRN) is the main source of inhibition in
the thalamus; it sends dense inhibitory projections to thalamic nuclei including a key structure in the ascending
auditory pathway, the medial geniculate body (MGB). MGB is comprised of excitatory thalamic relay cells that
project to the auditory cortex (AC) wherein auditory information is then decoded. Additionally, the MGB relay
cells send collaterals to TRN to provide feedback. Although TRN is necessary for transfer of important acoustic
information to higher-order structures in the auditory pathway, TRN's function at the cellular level in remains
poorly characterized. The goal of this proposal is to identify the function of different inhibitory
neuronal subtypes in TRN in auditory processing. TRN is comprised entirely of GABAergic inhibitory
neurons, of which the two dominant sub-classes are parvalbumin- (PV) and somatostatin- (SOM) positive
neurons, with a subset of TRN neurons co-expressing both neurotransmitters. In AC, PV and SOM neurons
differentially modulate frequency-dependent responses and differentially control adaptation in excitatory
cortical neurons. However, to date, little is known of the function of these two inhibitory neuronal subtypes in
the TRN. Moreover, their anatomical characterization remains limited. In this proposal, I will test the hypothesis
that PV and SOM neurons in TRN target distinct sub-nuclei of the MGB, exhibit unique sound-response
properties, and differentially modulate sound responses in MGB. To test this hypothesis, I will combine state-
of-the-art anatomical tracing, optogenetic, and electrophysiological approaches. With novel tracing techniques,
I will establish the anatomical connectivity between PV+ and SOM+ neurons of TRN and the MGB. Furthermore,
I will use optogenetics and electrophysiological approaches to functionally characterize how PV and SOM
neurons of TRN are modulating sound responses in the MGB. Combined, these results will reveal critically
important information about the differential function of inhibitory neurons at the level of the auditory thalamus,
an essential processing station in the auditory pathway.

## Key facts

- **NIH application ID:** 10349497
- **Project number:** 5F31DC018473-02
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Solymar Rolon-Martinez
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $33,253
- **Award type:** 5
- **Project period:** 2020-09-09 → 2022-09-08

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10349497

## Citation

> US National Institutes of Health, RePORTER application 10349497, The function of thalamic inhibition in auditory processing (5F31DC018473-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10349497. Licensed CC0.

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