A miniature fluorescence microscope for multi-plane imaging

Area of Science:

• Neuroscience
• Biomedical Engineering
• Optical Imaging

Background:

• Miniature fluorescence microscopes are crucial for studying neural circuits in freely moving animals.
• Current limitations exist in imaging neural activity across multiple depths in dynamic conditions.

Purpose of the Study:

• To develop a lightweight, one-photon microscope with dynamic focal plane adjustment.
• To improve the efficiency of imaging neural circuits in vivo.

Main Methods:

• A novel one-photon microscope design utilizing a variable focus liquid lens.
• Dynamic focal plane modulation synchronized with the image sensor.
• In vivo imaging of GCaMP7f expressing neurons in the mouse medial prefrontal cortex (mPFC).

Main Results:

• The microscope successfully imaged neurons across an axial scan of approximately 60 micrometers.
• Achieved a ~40% increase in the total number of neurons imaged compared to single-plane imaging.
• Demonstrated feasibility during open field tests in freely moving mice.

Conclusions:

• The proposed microscope design enables dynamic depth imaging, significantly increasing neuron capture.
• This technology offers enhanced capabilities for investigating neural circuits in behaving animals.
• The system provides a valuable tool for advancing neuroscience research.