# The Role of Parafascicular Thalamic Circuits in Action Generation

> **NIH NIH R01** · DUKE UNIVERSITY · 2022 · $401,180

## Abstract

Project Summary
The parafascicular nucleus is a major nucleus in the so-called intralaminar group. Although it is
traditionally considered part of the reticular activating system and thought to play a role in
arousal and attention, its contributions to behavior are still poorly understood. Much of the work
on the Pf was done in primates before the development of modern intersectional strategies for
selective cell type targeting and neural circuit dissection. This proposal aims to elucidate the
computational functions of specific components of the Pf circuit, and to determine how this
circuit can be used for the control of attention and action selection. Preliminary results indicate
that the Pf plays a key role in rapid action generation, which appears to be mediated by direct
excitatory inputs from the deep/intermediate layers of the superior colliculus. Two populations
of Pf projection neurons target different downstream structures and have distinct behavioral
functions. We hypothesize that Pf projections to the subthalamic nucleus are especially
important for fast action initiation that bypasses the canonical basal ganglia circuitry, where as
the well-known Pf projections to the striatum is not needed for action initiation, suggesting that
the Pf-basal ganglia pathway has a distinct function. A highly integrative approach will be
employed, combining 1) Motion capture for continuous behavioral quantification in 3D; 2)
wireless in vivo recording from single neurons; 3) optogenetic manipulation of defined neuronal
populations; 4) 1-photon calcium imaging of genetically defined individual neurons; and 5)
quantitative operant behavioral assays. These tools will be used to determine how the Pf
processes inputs from the midbrain and uses this information to guide action selection via
distinct output projections to the STN and striatum.

## Key facts

- **NIH application ID:** 10401927
- **Project number:** 5R01NS121253-02
- **Recipient organization:** DUKE UNIVERSITY
- **Principal Investigator:** Henry Yin
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $401,180
- **Award type:** 5
- **Project period:** 2021-05-15 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10401927

## Citation

> US National Institutes of Health, RePORTER application 10401927, The Role of Parafascicular Thalamic Circuits in Action Generation (5R01NS121253-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10401927. Licensed CC0.

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