# Molecular Multi-Species Approach for Trans-Synaptic Labeling of Neural Circuits - Diversity Supplement

> **NIH NIH RF1** · DARTMOUTH COLLEGE · 2021 · $233,172

## Abstract

PROJECT SUMMARY/ABSTRACT
It is estimated that the human brain contains an overwhelming 1015 synapses, structures essential for the normal
functioning of neural circuits. Our knowledge of the connections that form these critical signaling sites, in even
the simplest vertebrate nervous systems, is sorely lacking. Thus, a stated goal of this BRAIN initiative is to
“develop and validate novel tools to facilitate the detailed analysis of complex circuits and provide insights into
cellular interactions that underlie brain function”. This multi-PI collaborative project precisely addresses this goal.
It takes advantage of a powerful genetic technique, trans-Tango, that directs signaling across synapses to
identify both pre-synaptic neurons and their specific post-synaptic targets. The overall objectives of the proposed
experiments are three-fold: First, we will adapt the trans-Tango anterograde trans-synaptic signaling platform,
which was initially established and successfully implemented in the Drosophila model, to a vertebrate brain - that
of the zebrafish. The zebrafish is the organism of choice because of the ability to assay trans-Tango components
efficiently from injections of plasmid constructs into 1-cell embryos, and the ease and rapidity of generating
transgenic animals to activate trans-Tango in defined neuronal populations. Second, we will independently and
rigorously validate the neural connections revealed by trans-Tango as functional synaptic connections,
capitalizing on optogenetics, imaging techniques, and advanced microscopy methods. Owing to its transparency,
the larval zebrafish is ideally suited to verify synaptic connectivity in vivo using optical approaches. Third, we will
develop a new retrograde version of trans-Tango, which will allow identification of the pre-synaptic input of given
post-synaptic neurons. The modularity of trans-Tango permits efficient reconfiguration and optimization of the
system for accurate circuit
map
ping. The “retro-Tango” version will first be applied to Drosophila, building upon
lessons learned from the establishment of trans-Tango and, once optimal, introduced to the zebrafish nervous
system. By assembling the proposed genetic toolkit for anterograde and retrograde trans-synaptic tracing in both
invertebrate and vertebrate nervous systems, we expect these techniques to become widely used by the
neuroscience community and applied to additional experimental models. The strengths of this proposal are the
innovative strategies used to
map
neural connectivity, the compelling preliminary data, and the unique and
complementary expertise in molecular genetics, circuit neuroscience and microscopy design that the
collaborating researchers bring to the project.

## Key facts

- **NIH application ID:** 10286154
- **Project number:** 3RF1MH123213-01S1
- **Recipient organization:** DARTMOUTH COLLEGE
- **Principal Investigator:** Gilad Barnea
- **Activity code:** RF1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $233,172
- **Award type:** 3
- **Project period:** 2020-08-01 → 2022-09-19

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10286154

## Citation

> US National Institutes of Health, RePORTER application 10286154, Molecular Multi-Species Approach for Trans-Synaptic Labeling of Neural Circuits - Diversity Supplement (3RF1MH123213-01S1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10286154. Licensed CC0.

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