Simultaneous high-density 512-channel SiNAPS electrical recordings and optogenetics.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Implantable Electronics

Background:

• High-density CMOS neural probes offer single-neuron resolution for observing neural circuit activity.
• Optogenetic stimulation provides genetically selective control over neural cell activity.
• Combining these techniques is crucial for studying brain function and disease mechanisms.

Purpose of the Study:

• To develop a CMOS-based neural implant compatible with optogenetic stimulation.
• To address the challenge of photosensitivity in CMOS circuits causing signal artifacts.
• To enable simultaneous high-resolution neural recording and light-based neural modulation.

Main Methods:

• Designed and fabricated a 512-channel CMOS neural implant (SiNAPS) with a photoelectric shield.
• Arranged electrodes in 4 columns with a 29.5 μm pitch.
• Tested the probe's light sensitivity with and without the shield, and recorded in vivo light-evoked responses.

Main Results:

• Quantified the light sensitivity of the CMOS probe, demonstrating the effectiveness of the photoelectric shield.
• Successfully recorded light-evoked neural responses in vivo.
• Achieved recordings from over 180 neurons without light-induced electrophysiological signal distortion.

Conclusions:

• The developed SiNAPS neural implant effectively mitigates photoelectric artifacts caused by optogenetic stimulation.
• This shielded probe enables robust, simultaneous electrophysiological recording and optogenetic control.
• The technology advances the combined use of CMOS probes and optogenetics for neuroscience research.