Microinvasive Probes for Monitoring Electrical and Chemical Neural Activity in Nonhuman Primates

Area of Science:

• Neuroscience
• Biomedical Engineering
• Materials Science

Background:

• Accurate recording of neural activity is crucial for understanding brain function.
• Existing methods often struggle with simultaneous neurochemical and electrical recordings or require larger implants.
• Deep brain targets in primates present unique challenges for invasive recording techniques.

Purpose of the Study:

• To develop and validate novel microinvasive probes for simultaneous dual neurochemical and electrical neural activity recording.
• To enable high-resolution measurements from deep brain targets in primates.
• To assess the long-term stability and functionality of these probes.

Main Methods:

• Carbon fiber materials were used to fabricate shaft-assisted microinvasive probes (s-μIPs) with a 10 μm distal recording site.
• Probes were designed for compatibility with standard primate intracranial insertion protocols.
• Dual-channel probes were implanted in task-performing monkeys for simultaneous recording of dopamine, spikes, and local field potentials.

Main Results:

• The s-μIPs successfully provided simultaneous neurochemical (dopamine) and electrical (spikes, LFP) recordings with micrometer spatial resolution.
• Recordings were achieved from deep brain targets in primates using conventional cranial chambers.
• Functional multimodal recordings were maintained for over 1 year postimplantation.

Conclusions:

• Shaft-assisted microinvasive probes (s-μIPs) offer a viable solution for high-resolution, multimodal neural recordings in deep brain targets.
• These probes facilitate long-term, simultaneous measurement of neurochemical and electrical neural activity in behaving primates.
• The technology advances the capability for studying complex brain functions related to reward and movement.