# The regulation of synaptic specificity in the mammalian retina

> **NIH NIH R00** · BAYLOR COLLEGE OF MEDICINE · 2020 · $249,000

## Abstract

Abstract
Establishing proper retinal circuitry remains a central issue in visual system development. How neurons find
their correct target remains largely unknown. The first synapse in the retina provides a simple and
experimentally tractable system to explore the basis of synaptic specificity. Rod and cone photoreceptors
synapse selectively with rod bipolars and cone bipolars, respectively. To identify the molecular mechanism
mediating specificity, I generated transcriptome profiles of the different photoreceptors and their corresponding
bipolar cell targets during synaptogenesis. From these data sets, I find distinct transcripts encoding cell surface
and secreted proteins as promising candidates for this process. Using in vivo genetic manipulations and
developmental approaches, I will assess the function of these genes in establishing proper connectivity. From
my initial screen, I find the following: 1) non-canonical Wnt signaling between rods and rod bipolars is
responsible for dictating the position of the synaptic layer, 2) Rspo2 in rods is involved in layer segregation,
and 3) Nrcam in cones mediates selective connectivity to cone bipolars. I subdivided this proposal into two
parts where I study rod-to-rod bipolar connectivity in Aim 1 and address cone-to-cone bipolar connectivity in
Aim 2. The first section of each aim involves expanding on my preliminary findings and will be completed in the
K99 phase. The second part involves continue screening and expanding on the new phenotypes which will be
initiated under the mentorship of Dr. S. Lawrence Zipursky and will be completed during the R00 phase.
This project has been designed to facilitate Dr. Zuniga-Sanchez to obtain a position as a tenure-track Assistant
Professor at a top-tier academic research institution. With the help of her mentor and Advisory Committee, she
has generated promising data and made significant progress on her research. As an independent investigator,
she plans to continue her work studying the development of the mammalian retina with a clear relevance to
human health. During the K99 phase, she will continue benefiting from the mentorship on the developing visual
system from Dr. Zipursky. She will also receive additional career and scientific guidance at regular scheduled
meeting and presentations with her Advisory Committee. Dr. Zuniga-Sanchez will participate in career
development workshops offered through UCLA in preparation to apply for faculty positions and transitioning to
the R00 phase. This grant proposal outlines the training, resources, and network of collaborations needed to
establish Dr. Zuniga-Sanchez as an independent investigator in the vision field.

## Key facts

- **NIH application ID:** 10151683
- **Project number:** 4R00EY028200-03
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Elizabeth Zuniga-Sanchez
- **Activity code:** R00 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $249,000
- **Award type:** 4N
- **Project period:** 2020-07-01 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10151683

## Citation

> US National Institutes of Health, RePORTER application 10151683, The regulation of synaptic specificity in the mammalian retina (4R00EY028200-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10151683. Licensed CC0.

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