# Label-free Optical Recording of Neuroelectric Activities

> **NIH NIH R01** · STANFORD UNIVERSITY · 2021 · $434,139

## Abstract

Project Summary
Understanding how a network of interconnected neurons receives, stores and processes information requires
parallel and high quality recording of neuroelectric signals. Intracellular recording techniques such as patch
clamp are invasive and limited to recording 1-2 cells. While extracellular multielectrode arrays can record multiple
cells, they are pre-fabricated and thus can only probe fixed locations. Optical detection of electric activities
provides the needed spatial flexibility. Calcium sensors such as GcaMP have a slow time response and not
suitable to record fast-spiking pacemaker neurons such as dopaminergic neurons. Voltage-sensitive
fluorescence proteins and dyes have much faster time response, but their recording time is usually limited by
photobleaching.
In this project, we will demonstrate an orthogonal approach of optical recording. This method, Electrochromic
Optical Recording of Electric potentials (ECORE) makes use of a unique material property – optical absorption
of an electrochromic film depends on applied voltages. We detect the optical reflection of an electrochromic film
to read out cellular electrical activities. The method is truly label-free, i.e. free of any molecular probes that need
to be incorporated into cells and perturb cellular physiology, and not limited by photobleaching or photo-toxicity.
In preliminary work, we have built a sensitive optical setup that is able to detect the reflectivity change of the
electrochromic film in response to electrical potentials as small as 10 microvolts. Indeed, we have used ECORE
to successfully record single-cell action potentials in neurons, cardiomyocytes, and brain tissues. With this
project, we plan to dramatically expand ECORE capabilities by developing a scanning ECORE platform for
parallel detection and an ECORE microscope for subcellular measurement of neuroelectric activities. We will
use ECORE to probe the functional connectivity of dopaminergic neurons in midbrain area. Accomplishment of
this work will result in a new class of electrophysiological tools that can be used by other research groups.

## Key facts

- **NIH application ID:** 10190148
- **Project number:** 1R01NS121934-01
- **Recipient organization:** STANFORD UNIVERSITY
- **Principal Investigator:** Bianxiao Cui
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $434,139
- **Award type:** 1
- **Project period:** 2021-03-01 → 2026-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10190148

## Citation

> US National Institutes of Health, RePORTER application 10190148, Label-free Optical Recording of Neuroelectric Activities (1R01NS121934-01). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10190148. Licensed CC0.

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