Postoperative Recovery and Stability of Chronic Intracranial Multielectrode Electroencephalography Recording in Rats

Area of Science:

• Neuroscience
• Surgical Procedures
• Electrophysiology

Background:

• Chronic multi-site intracranial electroencephalography (EEG) implantation allows simultaneous neural signal acquisition across brain regions.
• Post-surgical perturbations can compromise data quality and experimental timelines.

Purpose of the Study:

• To describe a standardized protocol for chronic multi-site intracranial EEG electrode implantation in Sprague-Dawley rats.
• To outline a structured post-implantation assessment workflow for monitoring early surgical effects and determining experimental readiness.

Main Methods:

• Stereotactic implantation of tungsten wire electrodes in the anterior cingulate cortex, hippocampus CA1, and entorhinal cortex using a minimally disruptive surgical strategy.
• Longitudinal evaluation of electrode localization accuracy, local field potential integrity, pain-related behavior, feeding behavior, and neuroinflammatory markers.
• Electrophysiological and behavioral assessments at predefined postoperative time points (baseline, days 1, 4, 7, 10, 13), with histological analysis for tissue response.

Main Results:

• The protocol provides operational criteria and assessment intervals for consistent monitoring of post-surgical effects.
• Data supports the characterization of local tissue responses and early recovery dynamics.
• The workflow enables informed decisions regarding the initiation of long-term neurophysiological recordings.

Conclusions:

• This standardized protocol ensures reliable intracranial EEG recordings by systematically monitoring recovery after electrode implantation.
• The structured assessment aids in optimizing the timing for downstream neurophysiological experiments, improving data integrity.
• This workflow is crucial for researchers utilizing chronic multi-site intracranial EEG in rodent models.