# Development of direction selectivity maps

> **NIH NIH R00** · VANDERBILT UNIVERSITY · 2022 · $249,000

## Abstract

How does our ability to detect motion develop and to what extent does sensory experience contribute? In
mice, the detection of motion begins in the retina. There, direction selective ganglion cells (DSGCs) fire more
action potentials in response to visual stimuli moving in one direction, called the preferred direction, than visual
stimuli moving in the opposite direction, called the null direction. In the adult retina, the preferred directions of
DSGCs cluster along 4 directions. The relative orientation of these clusters varies across the surface of the retina,
creating a direction selectivity map. The factors which underlie the development of the direction selectivity map
is unknown. Two recent experiment indicate visual experience is involved. The first is that the preferred direction
of DSGCs cluster along the axes defined by optic flow, i.e. the trajectories of apparent motion mapped onto the
retinal surface. The second is from the Feller lab showing that the clustering of DSGCs preferred directions along
the 4 axes requires visual experience. In Aim1, I present strong preliminary evidence that demonstrates that the
map is established at eye-opening and is not altered after visual deprivation, contradicting a role for activity.
 Although visual experience does not seem necessary for establishing the direction selectivity map, it may
play a role in refining it. For example, raising a mouse in an artificial environment that enriches for specific
orientations leads to an overrepresentation of cortical cells that prefer that orientation and the process is thought
to be instructive rather than permissive. Therefore, in specific aim 2, I will determine whether altered visual
experience, specifically enriched for optic flow, refines the direction selectivity map.
 Finally, in Aim 3, we explore the factors that influence the organization of the direction selectivity map
at eye opening. First, we test whether retinal waves, which are spontaneous depolarizations of retinal ganglion
cells that occur exclusively during the first two weeks of postnatal life, play a role. These waves are the primary
driver of activity before eye opening in the direction selectivity circuit and even exhibit a propagation bias toward
forward optic flow. We propose a pharmacogenetic experiments to determine whether disruption of retinal waves
alters the organization of the map. Second, we begin to explore the role of transient molecular gradients that are
expressed in the retina when the direction selectivity circuit is developing. Specifically, I provide evidence that
the EphB receptor of the ephrinB axon guidance molecule exhibits a similar distribution gradient as the dorsal-
ventral DSGC preferred directions. We will then look at maps in a mouse lacking EphB receptors in the retina.

## Key facts

- **NIH application ID:** 10666013
- **Project number:** 4R00EY030909-03
- **Recipient organization:** VANDERBILT UNIVERSITY
- **Principal Investigator:** Alexandre Tiriac
- **Activity code:** R00 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $249,000
- **Award type:** 4C
- **Project period:** 2020-08-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10666013

## Citation

> US National Institutes of Health, RePORTER application 10666013, Development of direction selectivity maps (4R00EY030909-03). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10666013. Licensed CC0.

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