# Photoreceptor Terminal Differentiation: Photoreceptor Synaptogenesis

> **NIH NIH R01** · TRUSTEES OF INDIANA UNIVERSITY · 2020 · $379,467

## Abstract

Project Summary:
Delineating the conserved fundamental processes of photoreceptor differentiation and the maintenance of
neuronal identity will be applicable to and required for developing therapeutic interventions for both retinal
and neuronal degenerative diseases. To date, the molecular networks required for specifying neuronal cell
types, including photoreceptors, have been investigated thoroughly, but the molecular and cellular
mechanisms that promote and maintain photoreceptor identity remain poorly understood. Our proposed
work utilizes the paradigm of Glass mediated differentiation. Our recent results demonstrate that Glass
choreographs the expression of a network of genes required for all aspects of photoreceptor differentiation.
Thus this research leverages the genetic strengths of Drosophila neuronal development to investigate and
reveal mechanisms required for the differential assembly, functional maturity, and maintenance of
photoreceptor synapses. As such: Aim 1 will test our working hypothesis that the Glass downstream target
neto2, encoding an evolutionary conserved accessory protein of kainate receptors, is required for the
assembly of the photoreceptor synapses and integrity of the photoreceptors. Aim 2 investigates and
determines the molecular basis of and the functional significance of the interaction between Neto proteins
and kainate receptors with respect to assembly of synapses and maintaining photoreceptor integrity. Lastly,
Aim 3 develops an innovative inducible methodology that will permit the investigation whether retinal
degeneration in neto2 mutant animals is due to defects in synapse formation or homeostasis. Ultimately,
medicine's goal of advanced techniques for rehabilitation in cases of replacement, degeneration or injury is
contingent on an understanding of the various effects of genetic and environmental perturbations on
neuronal differentiation. The proposed research will establish foundational knowledge of photoreceptor
differentiation that will have widespread impacts on understanding and developing treatments for numerous
diseases from retinal degeneration to epilepsy to neuropathic pain.

## Key facts

- **NIH application ID:** 9987620
- **Project number:** 5R01EY026077-05
- **Recipient organization:** TRUSTEES OF INDIANA UNIVERSITY
- **Principal Investigator:** Andrew Zelhof
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $379,467
- **Award type:** 5
- **Project period:** 2016-08-01 → 2022-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9987620

## Citation

> US National Institutes of Health, RePORTER application 9987620, Photoreceptor Terminal Differentiation: Photoreceptor Synaptogenesis (5R01EY026077-05). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/9987620. Licensed CC0.

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