# Readout of fluorescence functional signals through highly scattering tissue

## TL;DR

This paper demonstrates that functional fluorescence signals from sources beneath highly scattering tissue can be effectively retrieved using matrix factorization algorithms, overcoming previous limitations in non-invasive optical recordings.

## Contribution

The study introduces a novel approach employing matrix factorization to extract functional signals through highly scattering tissue, enabling non-invasive optical brain activity monitoring.

## Key findings

- Successful retrieval of fluorescence signals through scattering tissue
- Effective demixing of signals from speckle patterns
- Potential for non-invasive brain activity imaging

## Abstract

Fluorescence is a powerful mean to probe information processing in the mammalian brain. However, neuronal tissues are highly heterogeneous and thus opaque to light. A wide set of non-invasive or invasive techniques for scattered light rejection, optical sectioning or localized excitation, have been developed, but non-invasive optical recording of activity through highly scattering layer beyond the ballistic regime is to date impossible. Here, we show that functional signals from fluorescent time-varying sources located below an highly scattering tissue can be retrieved efficiently, by exploiting matrix factorization algorithms to demix this information from low contrast fluorescence speckle patterns.