Multi-Frequency Interpolation X-talk Removal Algorithm: Enabling Combinations of Concurrent Optogenetics and Lock-in...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Optical Engineering

Background:

• Simultaneous fiber photometry and optogenetics is crucial for understanding neuronal circuit dynamics.
• Spectral overlap between optogenetic light and photometry detection hinders simultaneous all-optical recordings, especially in small brains.
• Existing methods struggle to isolate photometry signals when contaminated by optogenetic stimulation light.

Purpose of the Study:

• To develop and validate a novel algorithm for removing spectral crosstalk in simultaneous fiber photometry and optogenetics.
• To enable robust all-optical interrogation of neural circuits by overcoming spectral interference.

Main Methods:

• Demonstration of the multi-frequency interpolation X-talk removal (MuFIX) algorithm.
• Utilizing lock-in amplification with multifrequency signals to model and interpolate crosstalk-affected data.
• Validation using simulated and empirical data from small model organisms.

Main Results:

• MuFIX accurately recovers photometry signals contaminated by optogenetic crosstalk (R² ≈ 1.0, Pearson's r ≈ 1.0).
• The algorithm successfully interpolates across crosstalk-affected segments, closely matching non-crosstalk photometry.
• MuFIX demonstrates high fidelity in reproducing original signals after simulated crosstalk contamination.

Conclusions:

• MuFIX provides an effective solution for spectral overlap issues in simultaneous fiber photometry and optogenetics.
• This algorithm significantly expands the feasibility of all-optical approaches in neuroscience research.
• Adoption of MuFIX will facilitate previously impossible experimental designs for studying neural networks.