# The Role of LGN Directional Selectivity in Visual Cortical Processing

> **NIH NIH R21** · UNIVERSITY OF CONNECTICUT STORRS · 2020 · $241,500

## Abstract

PROJECT SUMMARY
The lateral geniculate nucleus (LGN) of rabbits and rodents contains a population of neurons that
show strong directional selectivity (DS) to visual stimulation. Although these LGN DS neurons are
known to project to the primary visual cortex (V1), their synaptic targets, and their role in the synthesis
of V1 receptive fields are unknown. Whereas in cats and primates, LGN neurons display little or no
orientation and directional selectivity and these properties are thought to be largely synthesized within
V1, in rabbits and rodents these properties could potentially be inherited, in part, from the LGN DS
neurons. The proposed experiments will address this question, aiming to understand how LGN DS
neurons contribute to the synthesis of the diverse receptive field seen in V1 neurons. This will be
accomplished using two sets of complementary methods, in fully awake rabbits. First (Aim 1), we will
determine which layers of V1 receive a strong input from LGN DS neurons. We will do this using
single-axon spike-triggered current source-density analysis, a method that provides a view of the
laminar profile of the presynaptic (axonal) and monosynaptic local field potentials and currents
generated by the spikes of single thalamocortical neurons within the topographically aligned region of
recipient cortex. Next (Aim 2), we will record the spike trains of both LGN DS neurons, and
retinotopically aligned cortical neurons of different receptive field classes. We will determine which
cortical neurons within the synaptic recipient zone of the LGN DS neuron receives synaptic input
(using methods of extracellular cross-correlation), and how the directional preferences of the LGN DS
neurons relate to the preferences of their synaptic targets. Direction and orientation selectivity are
among the most salient response properties of visual cortical neurons and this project is aimed at
understanding how these properties emerge.

## Key facts

- **NIH application ID:** 9896181
- **Project number:** 1R21EY030291-01A1
- **Recipient organization:** UNIVERSITY OF CONNECTICUT STORRS
- **Principal Investigator:** HARVEY A SWADLOW
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $241,500
- **Award type:** 1
- **Project period:** 2020-09-01 → 2022-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9896181

## Citation

> US National Institutes of Health, RePORTER application 9896181, The Role of LGN Directional Selectivity in Visual Cortical Processing (1R21EY030291-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9896181. Licensed CC0.

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