# All optical in vivo cardiac electrophysiology at cellular resolution

> **NIH NIH R21** · MASSACHUSETTS GENERAL HOSPITAL · 2020 · $207,964

## Abstract

Current models of cardiac electrophysiology and arrhythmia focus on the electrical properties of the
cardiomyocyte. Recent investigations, though, have begun to establish remarkable roles for non-myocyte cell
types, including fibroblasts and immune cells, in cardiac conduction and electrical remodeling after injury. The
concept that conduction in the heart depends upon multiple cell types has the potential to alter many of our
current hypotheses about arrhythmia generation and promises entirely new approaches to therapy.
Revolutionary advances in microscopy, transgenic mouse models, fluorescent reporters, and optogenetics
tools are fueling paradigm shifts in our understanding of complex cellular neuronal physiology in the brain. Yet
investigations into cellular connectivity in the heart to date have depended upon in vitro examinations of
electrophysiology (patch clamping, co-culture) or low resolution readouts of conduction (ECG, conventional
optical mapping). This Trailblazer R21 application proposes to overcome limitations of standard optical
mapping approaches by creating a new platform for in vivo all-optical electrophysiology studies in the beating
heart at cellular resolution. Aim 1 proposes to combine high resolution cardiac intravital microscopy techniques
with multiplexed fluorescent reporters and cell-specific optogenetics actuators to enable simultaneous optical
mapping and stimulation of electrical activity in the mouse heart with cellular resolution. Aim 2 will then apply
this platform to study the electrical connectivity of myocytes and non-myocytes during healing after myocardial
infarction. If successful, this application will significantly advance the fields of cardiac imaging and
electrophysiology and will address key questions with clinical implications about electrical remodeling and
models of arrhythmia generation after myocardial infarction.

## Key facts

- **NIH application ID:** 9994916
- **Project number:** 5R21EB026762-03
- **Recipient organization:** MASSACHUSETTS GENERAL HOSPITAL
- **Principal Investigator:** Aaron D Aguirre
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $207,964
- **Award type:** 5
- **Project period:** 2018-09-30 → 2023-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9994916

## Citation

> US National Institutes of Health, RePORTER application 9994916, All optical in vivo cardiac electrophysiology at cellular resolution (5R21EB026762-03). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9994916. Licensed CC0.

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