High-density transparent graphene arrays for predicting cellular calcium activity at depth from surface potential...

Area of Science:

• Neuroscience
• Materials Science
• Bioengineering

Background:

• Optically transparent neural microelectrodes enable simultaneous optical and electrical recordings of neural activity.
• Scaling down electrode dimensions and increasing density are crucial for high-resolution neural recording and capturing complex dynamics.

Purpose of the Study:

• To develop high-density, transparent graphene microelectrode arrays with ultrasmall openings for single-cell resolution neural recordings.
• To overcome limitations of current neural probes for advanced brain activity monitoring.

Main Methods:

• Fabrication of transparent graphene microelectrodes with platinum nanoparticle enhancement and interlayer-doped double-layer graphene.
• High-density arrays with up to 256 channels and 20 µm electrode diameter.
• Multimodal experiments combining electrophysiological recordings with two-photon calcium imaging in mouse visual cortex.

Main Results:

• Visually evoked responses were spatially localized in high-frequency bands, especially multiunit activity.
• Multiunit activity power correlated with cellular calcium activity.
• Single-cell and average calcium activities were successfully decoded from surface potentials using dimensionality reduction and neural networks.

Conclusions:

• High-density transparent graphene microelectrode arrays offer a powerful tool for high-resolution neural recording.
• These arrays facilitate decoding of neural activity, bridging electrophysiology and optical imaging.
• The developed technology advances the potential for understanding nonlinear neural dynamics and developing brain-computer interfaces.