Primary Somatosensory to Motor Cortex Microstructural Connectivity Predicts the Mu-Rhythm Phase Effect on...

Area of Science:

• Neuroscience
• Motor Control
• Brain Connectivity

Background:

• Sensorimotor rhythms, specifically the mu-rhythm, are known to influence corticospinal excitability.
• Individual variability exists in how mu-rhythm phase impacts neural activity.
• This variability may be linked to the physical connections within the brain.

Purpose of the Study:

• To investigate the relationship between sensorimotor mu-rhythm phase and corticospinal excitability.
• To explore whether microstructural connectivity between the primary somatosensory cortex (S1) and motor cortex (M1) influences this relationship.

Main Methods:

• Electrophysiological recordings to measure mu-rhythm phase.
• Transcranial magnetic stimulation (TMS) to assess corticospinal excitability.
• Diffusion tensor imaging (DTI) to quantify S1-M1 microstructural connectivity.

Main Results:

• Mu-rhythm phase significantly modulates corticospinal excitability.
• A positive correlation was found between S1-M1 microstructural connectivity and the magnitude of the mu-phase effect.
• Individuals with higher S1-M1 connectivity exhibited a stronger influence of mu-phase on corticospinal excitability.

Conclusions:

• Microstructural integrity of the S1-M1 pathway is a key factor in modulating corticospinal excitability by sensorimotor mu-rhythm.
• Understanding individual differences in brain connectivity can help predict responses to interventions targeting sensorimotor pathways.