Evaluating task-evoked neurovascular coupling using integrated OPM-MEG and fNIRS imaging.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Imaging

Background:

• Neurovascular coupling (NVC) is crucial for brain function and functional magnetic resonance imaging (fMRI).
• Simultaneous measurement of hemodynamic and neuronal activity is needed to fully characterize NVC.
• Existing methods may have limitations in temporal resolution or invasiveness.

Purpose of the Study:

• To develop and validate a combined system for simultaneous, non-invasive measurement of hemodynamic and neuronal responses.
• To characterize NVC using this novel setup during motor tasks.
• To provide a framework for studying NVC in various populations.

Main Methods:

• Combined an in-house functional near-infrared spectroscopy (fNIRS) system with optically pumped magnetometer-based magnetoencephalography (OPM-MEG).
• Utilized a custom 3D-printed helmet based on individual MRI for precise sensor placement.
• Participants performed self-paced motor tasks (ball squeeze, finger opposition).

Main Results:

• Observed expected hemodynamic changes (oxy- and deoxy-hemoglobin) with fNIRS.
• Detected robust beta-band desynchronization and post-movement synchronization with OPM-MEG.
• Found a typical lag of 4-7 seconds between neuronal and hemodynamic responses, with stronger correlations in alpha-band for finger opposition tasks.

Conclusions:

• The combined OPM-MEG and fNIRS system enables simultaneous, non-invasive assessment of NVC.
• The study provides a validated framework for NVC research in healthy and clinical settings.
• Results offer insights into the temporal dynamics of neurovascular interactions during motor control.