MATRIEX imaging: multiarea two-photon real-time in vivo explorer

Area of Science:

• Neuroscience
• Microscopy
• In vivo imaging

Background:

• Two-photon laser scanning microscopy is crucial for studying neuronal activity in mammalian brains at cellular resolution.
• Current limitations restrict these studies to single functional brain regions.
• Understanding brain-wide neural circuits requires methods capable of multi-region analysis.

Purpose of the Study:

• To introduce a novel technique, the multiarea two-photon real-time in vivo explorer (MATRIEX), for simultaneous in vivo imaging of neuronal activity across multiple distributed brain regions.
• To enable high-resolution, single-cell level functional exploration of brain-wide neural circuits.

Main Methods:

• Developed the MATRIEX technique enabling targeting of multiple functional brain regions within a 12 mm diameter zone.
• Achieved simultaneous two-photon Ca2+ imaging with single-cell resolution across distributed fields of view (~200 μm diameter each).
• Demonstrated MATRIEX on anesthetized and awake mice, imaging primary visual cortex, primary motor cortex, and hippocampal CA1 region.

Main Results:

• Successfully demonstrated real-time functional imaging of single-neuron activities in multiple, spatially distributed brain regions simultaneously.
• Showcased the ability to image neuronal activity across macroscopic distances (>1 mm) both laterally and axially using a single laser scanning device.
• Validated the MATRIEX technique's effectiveness in both anesthetized and awake animal models.

Conclusions:

• The MATRIEX technique provides a powerful new tool for exploring multiarea neuronal activity in vivo.
• It facilitates the study of brain-wide neural circuit function with unprecedented single-cell resolution.
• MATRIEX can be easily integrated as an add-on module for existing two-photon microscopes, enhancing their capabilities without modification.