Functional imaging through scattering medium via fluorescence speckle demixing and localization.

Area of Science:

• Neuroscience
• Optical Imaging
• Biophysics

Background:

• Fluorescence-based optical techniques are valuable for mammalian brain research.
• Light scattering in biological tissues limits deep neuron imaging.
• Non-invasive deep brain functional imaging remains a significant challenge.

Purpose of the Study:

• To develop a method for locating individual fluorescent emitters deep within scattering biological tissues.
• To overcome limitations of current optical techniques for deep brain imaging.
• To enable non-invasive functional imaging at depth.

Main Methods:

• Utilized a matrix factorization algorithm to analyze low-contrast fluorescent speckle patterns.
• Applied the algorithm to retrieve functional signals from time-varying fluorescent emitters behind scattering samples.
• Tested the approach using scattering phantoms and a biological brain slice (~200 µm).

Main Results:

• Successfully located individual fluorescent emitters even with background fluorescence.
• Demonstrated the capability to image temporal activity of large groups of emitters.
• Validated the method's effectiveness in mimicking biological tissue conditions.

Conclusions:

• The matrix factorization approach effectively deciphers fluorescent speckle patterns for emitter localization.
• This method offers a promising solution for non-invasive deep brain imaging.
• The technique advances the ability to probe neural activity at greater depths within the brain.