MiniFAST: a sensitive and fast miniaturized microscope for in vivo neural recording

Area of Science:

• Neuroscience
• Biomedical Engineering
• Microscopy

Background:

• Observing neural activity in vivo is crucial for understanding brain function.
• Current miniaturized microscopes have limitations in frame rate, sensitivity, and resolution.
• Emerging neural indicators like genetically encoded voltage indicators (GEVIs) require high-speed imaging.

Purpose of the Study:

• To integrate an advanced CMOS image sensor into an open-source miniaturized microscope platform.
• To develop a microscope with enhanced capabilities for neural imaging.

Main Methods:

• Integration of an advanced CMOS image sensor into a miniaturized microscope.
• Development of MiniFAST, a microscope with 1080p video, 1.5 μm resolution, and up to 500 Hz frame rates.
• High gain capability (up to 70 dB) for low-light imaging.

Main Results:

• Achieved ~300-Hz in vivo imaging of freely behaving mice using GCaMP6f.
• Demonstrated high-speed 500-Hz in vitro imaging of a GEVI.
• Successfully performed in vivo GEVI imaging in head-fixed mice.

Conclusions:

• MiniFAST significantly extends miniaturized microscope capabilities.
• The developed microscope offers improvements in high-speed imaging, sensitivity, and resolution.
• This advancement supports broader applications in neuroscience research.