ElectroFluor Voltage-Sensitive Dyes: Comprehensive Analysis of Wavelength-Dependent Sensitivity and Cross-Channel...

Area of Science:

• Neuroscience
• Biophotonics
• Optical Imaging

Background:

• Voltage-sensitive dyes are crucial for monitoring neuronal activity.
• Green fluorescent protein (GFP) indicators have limitations in spectral range and excitation.
• New ElectroFluor (EF) dyes offer broader spectral emission, including near-infrared.

Purpose of the Study:

• To evaluate the performance of EF-530, EF-630, and EF-730p dyes in neuronal tissue.
• To compare spectral orthogonality and cross-channel bleed-through with GFP indicators.
• To quantify EF dye performance for population voltage imaging in the mouse cerebral cortex.

Main Methods:

• Side-by-side comparison of EF dyes (EF-530, EF-630, EF-730p) in mouse cerebral cortex slices.
• Population voltage imaging at optimal excitation wavelengths (530, 630, 730 nm).
• Assessment of cross-channel signal bleed-through across multiple excitation wavelengths (475, 530, 630, 730 nm).

Main Results:

• All tested EF dyes produced robust optical signals at their optimal excitation wavelengths.
• Distinct amplitudes, polarities, and photobleaching patterns were observed in non-preferred excitation channels.
• Significant cross-channel bleed-through was quantified, varying between dyes and wavelengths.

Conclusions:

• EF dyes demonstrate potential for neuronal population imaging outside the conventional GFP excitation range.
• Understanding bleed-through characteristics is essential for accurate interpretation of EF dye signals.
• These findings provide critical quantitative data for optimizing EF dye application in neuroscience research.