# Development of 3D-FAST Optical Interface for Rapid Volumetric Neural Sensing and Modulation

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2021 · $2,665,761

## Abstract

Project Summary
To further our understanding of the function of neural circuits, there is a need for new tools that can
collect simultaneous measurements from large populations of neurons involved in a common neural
computation and provide precise functional modulation. Optical imaging in awake animals expressing
calcium or voltage indicators provides real-time functional and spatial information from individual
neurons within local neural circuits. The limitations of current imaging technology include small fields of
view encompassing single brain regions, and the requirement for head fixation, which prevents
naturalistic behavior. In addition, most optical imaging systems do not allow for simultaneous high-
resolution functional imaging in combination with spatially-localized optogenetic modulation.
To meet this challenge, we propose to develop an optical device (`3D-FAST') that allows for rapid, real-
time volumetric neural recording and precise optical stimulation. By pairing miniature arrays of
micropatterned LED emitters with the axial focusing capabilities of electrowetting lens technologies, we
will achieve duplex recording and stimulation of many thousands of neurons. Through utilization of novel
3D-printed scaffolding, we will be able to create modular, expandable, customizable lens arrays that
allow for recording of large-scale bi-directional neural interfaces for closed-loop modulation of neural
circuits.
We will create two versions of the 3D-FAST device. 3D-FAST-GECI that will provide fast, volumetric
imaging at 30 Hz for GCaMP imaging, and 3D-FAST-GEVI that will provide frame rates of 1 kHz at a
single plane combined with a slower, high resolution volume scan. Initially, the devices will be tested in
the anesthetized, and then awake, freely moving mouse for experiments using GCaMP, voltage indicators
ASAP and Voltron, and finally combining with localized optogenetics for closed loop feedback.
In sum, these experiments will demonstrate the unique capabilities of the 3D-FAST technology. Rapid,
imaging of improved voltage indicators will be paired with spatially-restricted light delivery for
optogenetic neural modulation for the first time in a freely moving mouse. The optical imaging properties
will be compared with ground-truth two-photon microscopy, and the functional consequence of
neuromodulation will be dissected through behavioral assays. The 3D-FAST tool will bring novel
capabilities to measuring and modulating large populations of neurons in freely-moving animals, to better
understand the neural computations that underlie behavior. In addition, this body of work will lay the
ground for future development of fully implantable optical recording and modulating units for use in
freely-moving, untethered naturalistic behavior experiments.

## Key facts

- **NIH application ID:** 10294019
- **Project number:** 1R01NS123665-01
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Emily Gibson
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $2,665,761
- **Award type:** 1
- **Project period:** 2021-09-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10294019

## Citation

> US National Institutes of Health, RePORTER application 10294019, Development of 3D-FAST Optical Interface for Rapid Volumetric Neural Sensing and Modulation (1R01NS123665-01). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10294019. Licensed CC0.

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