# Functional Properties of Neural Circuits for Vision

> **NIH NIH R01** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2022 · $539,434

## Abstract

Project Summary
For sensory systems, feedforward projections from thalamic relay cells provide the cortex with information about
the external environment. The cortex, in turn, sends extensive feedback to the thalamus. The cortex thus
functions both to process information supplied by the thalamus as well as to influence dynamically the
transmission of thalamic input. The primary goal of the experiments presented in this proposal is to determine
how the primary visual cortex (V1) and the lateral geniculate nucleus (LGN) of the thalamus interact to
dynamically influence visual processing. The study involves four sets of experiments. The first major series of
experiments (Specific Aim 1) will determine the functional topography of corticogeniculate feedback to the LGN
and will test the hypothesis that there is a center/surround organization of feedback with a central region
providing net excitation and a surround providing net suppression. The second series of experiments (Specific
Aim 2) will determine the influence of corticogeniculate feedback in augmenting extraclassical surround
suppression in the LGN and will reveal whether effects of feedback are specific for feedforward channels to
cortex. The third series of experiments (Specific Aim 3) will test the hypothesis that corticogeniculate feedback
serves to modulate retinogeniculate communication and to transform visual signals en route from retina to cortex.
The final series of experiments (Specific Aim 4) will uncover the interactions between corticogeniculate feedback
and visual attention and will determine whether attentional demand adjusts the dynamics of feedback effects on
visual signals relayed from thalamus to cortex. Given the central importance of corticothalamic pathways for
governing the excitability of thalamocortical networks, it is important that we understand the functional properties
of the corticothalamic pathway, as disorders of the pathway likely underlie several illnesses affecting vision and
visual processing.

## Key facts

- **NIH application ID:** 10468121
- **Project number:** 5R01EY013588-20
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** W MARTIN USREY
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $539,434
- **Award type:** 5
- **Project period:** 2001-07-05 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10468121

## Citation

> US National Institutes of Health, RePORTER application 10468121, Functional Properties of Neural Circuits for Vision (5R01EY013588-20). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10468121. Licensed CC0.

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