# Characterization of the Properties and Mechanisms of Photobiomodulation-Induced Axonal Block and Evaluation as a Treatment for Neuropathic Pain

> **NIH NIH R01** · CASE WESTERN RESERVE UNIVERSITY · 2022 · $546,928

## Abstract

Project Summary / Abstract
Recent research indicates that when ~808 to 830 nm light is applied in immediate juxtaposition to target neurons
or axons (within mm) through invasive techniques, C and Aδ fibers that convey pain-related information can
temporarily and reversibly be “turned off” without affecting the functionality of the larger A fibers. If further
developed, this photobiomodulation (PBM) effect has exciting possibilities as an implantable device-based
treatment for various chronic pain syndromes, including neuropathic pains. This project takes important steps to
develop fundamental and mechanistic understanding, and to provide a foundation for translation.
 In terms of fundamental and mechanistic understanding – first, the effect of PBM dose and wavelength on
axonal block (in an ex vivo peripheral nerve preparation) and nociceptive response (in an in vivo rodent pain
model) will be rigorously characterized. These data will provide important mechanistic insight and translational
value. Second, the role of observed microtubule destabilization and the resulting axonal varicosities will be
explored as contributors to the mechanism of the independently-observed action potential block. We will
determine whether or not there is a correlation between effect size (functional data) and degree of microtubule
instability (confocal microscopy and electron microscopy data). Computational models will be used to evaluate
the effect of axonal varicosities on action potential propagation. Finally, the effect of pharmacological microtubule
(de)stabilizers on PAB dose will be assessed.
 In terms of translational activities – the project includes development of pre-clinical-grade systems that allow
PBM at the nerve to be applied chronically with the ultimate goal of demonstrating that chronic PBM can provide
a persistent and profound analgesic effect in a large animal pain model (porcine). A fully implantable system
based on an existing commercial neurostimulator will enable PBM to be delivered over extended periods of time.
A percutaneous system will require repeated interventions over time (e.g., weekly interventions on the order of
minutes), but will enable use of higher peak powers not achievable with the fully implantable system. The
systems will be used in a porcine pain model (peripheral neuritis) that better mimicked the human response to
pharmacological interventions than rodent models have been able to do. The pre-clinical studies will include a
30-day pilot study followed by a 6-month study in minipigs.
 In summary, this project will expand fundamental understanding of PBM-induced axonal block with an eye
toward translational devices suitable for the treatment of chronic pain.

## Key facts

- **NIH application ID:** 10399588
- **Project number:** 5R01NS121372-02
- **Recipient organization:** CASE WESTERN RESERVE UNIVERSITY
- **Principal Investigator:** Juanita J Anders
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $546,928
- **Award type:** 5
- **Project period:** 2021-05-01 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10399588

## Citation

> US National Institutes of Health, RePORTER application 10399588, Characterization of the Properties and Mechanisms of Photobiomodulation-Induced Axonal Block and Evaluation as a Treatment for Neuropathic Pain (5R01NS121372-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10399588. Licensed CC0.

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