A wireless multi-channel neural amplifier for freely moving animals

Area of Science:

• Neuroscience
• Biomedical Engineering
• Animal Behavior

Background:

• Conventional neural recording systems limit behavioral studies to controlled indoor environments due to tethering cables.
• Existing wireless telemetry systems for rodents have limitations in channel count, weight, and transmission range.

Purpose of the Study:

• To develop a wireless, multi-channel neural recording system for freely behaving rats.
• To overcome the environmental and behavioral constraints imposed by traditional wired recording setups.

Main Methods:

• A wireless system was developed to acquire up to 64 voltage signals from implanted electrodes at 20 kHz.
• Signals were time-division multiplexed, transmitted via radio frequency up to 60 m, and recorded wirelessly.
• The system's electrode-referred noise was measured (<4 μV), comparable to wired systems.

Main Results:

• The wireless system demonstrated superior performance over existing rodent telemetry in channel count, weight, and transmission range.
• Neural population activity was successfully recorded outdoors and in tunnels, demonstrating effectiveness in diverse environments.
• Visual cortex neural firing was observed to be sparse, exhibit long-range correlations, and be influenced by locomotor activity.

Conclusions:

• The developed wireless neural recording system significantly enhances the ability to study brain activity in freely behaving animals.
• This technology facilitates novel research by enabling neural recordings in complex, naturalistic, and previously inaccessible environments.
• The findings provide insights into neural population dynamics, particularly in the visual cortex, during naturalistic behaviors.