High-density Electroencephalographic Acquisition in a Rodent Model Using Low-cost and Open-source Resources

Area of Science:

• Neuroscience
• Biomedical Engineering
• Electrophysiology

Background:

• Advanced electroencephalography (EEG) analysis, such as electrical source imaging and network connectivity, requires high spatial resolution.
• Traditional rodent EEG methods using screw electrodes lack the necessary electrode density for these advanced analyses.
• Existing high-density rodent EEG systems are often unavailable, lack durability for long-term studies, or are restricted to anesthetized subjects.

Purpose of the Study:

• To investigate a low-cost method for fabricating a durable, high-count transcranial electrode array for rodent EEG.
• To enable advanced EEG analyses, including source imaging and connectivity measures, in freely moving rodents.
• To present procedures for fabricating and surgically implanting headpieces for high signal-to-noise, low-impedance EEG and electromyography (EMG) signals.

Main Methods:

• Development and fabrication of a low-cost, high-density transcranial electrode array with bilaterally implantable headpieces.
• Surgical implantation procedures tailored for the smaller mouse skull, focusing on achieving high signal quality.
• Description of a system version with 26 EEG and 4 EMG channels, allowing tethered recordings in freely moving animals.

Main Results:

• The proposed method allows for the construction of a durable, high-count transcranial electrode array.
• The fabricated arrays facilitate high signal-to-noise, low-impedance EEG and EMG recordings.
• The system is demonstrated for use in freely moving mice, enabling advanced EEG analyses.

Conclusions:

• A feasible, low-cost method for creating high-density rodent EEG arrays is presented.
• This technology overcomes limitations of traditional methods, supporting advanced neuroscience research in rodents.
• The developed electrode system enhances the capability for studying brain activity in freely moving mice and rats.