Functional Near-Infrared Spectroscopy Reveals Functional Rewiring between Macaque Motor Areas Following...

Area of Science:

• Neuroscience
• Systems Neuroscience
• Rehabilitation Science

Background:

• Post-stroke motor recovery involves cortical reorganization.
• Functional near-infrared spectroscopy (fNIRS) is a potential tool for monitoring this process.
• Its feasibility for assessing functional connectivity changes during recovery needs validation.

Purpose of the Study:

• To develop and validate a high-density fNIRS system for measuring cortical activity in macaques.
• To assess changes in directed functional connectivity among motor cortical areas during post-stroke recovery.
• To evaluate the effectiveness of fNIRS in monitoring brain reorganization related to motor function restoration.

Main Methods:

• Utilized a high-density fNIRS system in two Japanese macaque monkeys.
• Collected data before and after induced focal infarcts and subsequent rehabilitation.
• Applied time-varying conditional Granger causality to analyze directed functional connectivity during hand movements.

Main Results:

• Revealed task-dependent directed functional connectivity among motor areas, indicating network reorganization.
• Observed ipsilesional hemisphere connectivity changes for small infarcts.
• Detected both contralesional and interhemispheric connectivity changes for larger infarcts.

Conclusions:

• Functional connectivity analysis using fNIRS is effective for monitoring brain functional changes during motor recovery.
• fNIRS can assess cortical reorganization associated with post-stroke motor recovery.
• Findings align with human and animal model studies of brain damage and recovery.