Double-μPeriscope, a tool for multilayer optical recordings, optogenetic stimulations or both

Area of Science:

• Neuroscience
• Systems Neuroscience
• Optical Engineering

Background:

• Mammalian cognitive functions rely on complex cortical microcircuits across six layers, involving diverse excitatory and inhibitory cells.
• Understanding these microcircuits necessitates simultaneous manipulation and monitoring across different cortical depths.
• Current techniques face limitations in depth-specific, multi-layer access without causing significant tissue damage.

Purpose of the Study:

• To present a simple, versatile method for delivering light to any two cortical layers simultaneously.
• To overcome limitations of existing techniques for multi-layer cortical circuit investigation.
• To facilitate mechanistic understanding of cortical microcircuits and their role in cognitive functions.

Main Methods:

• Development of a novel optical probe featuring two microprisms mounted on a single shaft.
• Demonstration of the probe's capability for simultaneous light delivery to two distinct cortical layers.
• Validation through three experimental paradigms: independent optogenetic manipulation, stimulation-monitoring, and simultaneous monitoring of thalamic axons in awake mice.

Main Results:

• Successful independent optogenetic manipulation of two distinct cortical layers.
• Effective stimulation of one layer while monitoring activity in another.
• Simultaneous monitoring of thalamic axon activity across two cortical layers in awake, behaving mice.

Conclusions:

• The developed optical probe offers a simple, versatile, small-sized, and low-cost solution for multi-layer cortical access.
• This technology enables simultaneous manipulation and monitoring, advancing the study of cortical microcircuits.
• The probe's design facilitates broad application for addressing key questions in neuroscience and cognitive function research.