Optetrode: a multichannel readout for optogenetic control in freely moving mice

Area of Science:

• Neuroscience
• Optogenetics
• Bioengineering

Background:

• Optogenetics enables precise control of neural circuits in vivo.
• Simultaneous optogenetic stimulation and electrophysiological recording in freely moving mice remain challenging.
• Existing methods lack the integration needed for complex circuit analysis.

Purpose of the Study:

• To design and validate a novel device, the optetrode, for combined optical stimulation and multichannel electrophysiological recording.
• To enable simultaneous manipulation and recording of neural activity in specific cell types in freely moving mice.
• To overcome the limitations of current techniques for studying neural circuits.

Main Methods:

• Developed a lightweight, compact, and robust optetrode using an optical fiber-centric coaxial design.
• Manufactured the optetrode with a low-cost, easily constructible approach.
• Validated the device's performance through stable, high-quality recordings for over 6 weeks post-implantation.

Main Results:

• The optetrode successfully enabled colocalized multi-tetrode electrophysiological recording and optical stimulation in freely moving mice.
• Demonstrated stable, high-quality neural recordings for at least 6 weeks.
• Quantified, for the first time, the response of genetically defined medial prefrontal cortex cell classes to optical stimulation during behavior.

Conclusions:

• The optetrode is a practical and effective tool for advancing optogenetic and electrophysiological research in behaving animals.
• This device facilitates the investigation of neural circuit function with unprecedented precision.
• The optetrode opens new avenues for understanding brain function in complex behaviors.