Non-Scanning Fiber-Optic Near-Infrared Beam Led to Two-Photon Optogenetic Stimulation In-Vivo

TL;DR

This paper introduces a novel non-scanning fiber-optic two-photon optogenetic stimulation method that enhances deep-brain neural activation in vivo, offering a less invasive and more precise alternative to traditional single-photon techniques.

Contribution

The study demonstrates the first in-depth in vivo application of non-scanning fiber-optic two-photon stimulation, improving deep-brain neural activation efficiency over conventional methods.

Findings

Enhanced in-depth stimulation efficiency compared to single-photon methods

Successful in vivo application in transgenic mouse models

Characterization of two-photon activation at various near-infrared laser parameters

Abstract

Stimulation of specific neurons expressing opsins in a targeted region to manipulate brain function has proved to be a powerful tool in neuroscience. However, the use of visible light for optogenetic stimulation is invasive due to low penetration depth and tissue damage owing to larger absorption and scattering. Here, we report, for the first time, in-depth non-scanning fiber-optic two-photon optogenetic stimulation (FO-TPOS) of neurons in-vivo in transgenic mouse models. In order to optimize the deep-brain stimulation strategy, we characterized two-photon activation efficacy at different nearinfrared laser parameters. The significantly-enhanced in-depth stimulation efficiency of FO-TPOS as compared to conventional single-photon beam was demonstrated both by experiments and Monte Carlo simulation. The non-scanning FO-TPOS technology will lead to better understanding of the in-vivo neural circuitry because this technology permits more precise and less invasive anatomical delivery of stimulation.