# Light-Induced Targeted Recombination Strategies For Genetic Access to Recently Active Neurons

> **NIH NIH R21** · WASHINGTON UNIVERSITY · 2020 · $484,032

## Abstract

PROJECT SUMMARY
A fundamental challenge in neuroscience is in understanding which circuits and cells in the brain contribute to
specific behaviors, perceptions, and functions. One class of tools that can help to unveil complex brain circuitry
are activity integrators that can record the history of neural activity over a user-specified window of time.
Technologies that not only record and map neural activity but enable genetic access to ‘playback’ neural activity
can provide an unparalleled understanding of brain circuit structures. This project will develop and validate new
optogenetic tools allowing permanent genetic access to recently activated neurons in vivo, within a time frame
specified using light. This project builds on a previously developed and validated optogenetic tool: a
photoactivatable DNA recombinase technology that shows low background, high induced activity, and a narrow
time window for activation. We will validate these tools in cultured cells and in vivo in mouse brain. With these
tools, users could apply a brief pulse of light during a behavior, resulting in a permanent genetic modification in
neurons active during the behavior. These precision tools will extend the genetic toolkit for neuroscientists and
enable a variety of new studies interrogating and manipulating complex brain circuitry in the normal and diseased
brain.

## Key facts

- **NIH application ID:** 9924856
- **Project number:** 1R21EY031269-01
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Aaron J Norris
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $484,032
- **Award type:** 1
- **Project period:** 2020-06-01 → 2023-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9924856

## Citation

> US National Institutes of Health, RePORTER application 9924856, Light-Induced Targeted Recombination Strategies For Genetic Access to Recently Active Neurons (1R21EY031269-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/9924856. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*