Noninvasive modulation of human corticostriatal activity.

Area of Science:

• Neuroscience
• Brain Stimulation
• Functional Neuroimaging

Background:

• Corticostriatal pathways are crucial for motor control and are implicated in various brain disorders.
• Noninvasive brain stimulation (NIBS) offers a promising avenue for modulating corticostriatal activity.
• A validated neuroimaging method to confirm NIBS-induced changes in corticostriatal activity is needed.

Purpose of the Study:

• To develop and validate a novel analysis framework (ISAAC) for disambiguating functional connectivity and local activity.
• To investigate the effects of transcranial static magnetic field stimulation (tSMS) on corticostriatal activity using resting-state functional MRI (fMRI).
• To demonstrate noninvasive modulation and monitoring of corticostriatal pathways in humans.

Main Methods:

• Development and validation of the Information Synthesis and Activity Classification (ISAAC) analysis framework.
• Application of tSMS to the supplementary motor area (SMA).
• Resting-state functional MRI (fMRI) to measure brain activity and functional connectivity before and after tSMS.

Main Results:

• The ISAAC framework successfully identified the SMA as a key cortical region connected to the striatum.
• tSMS of the SMA led to significant modulation of local activity in the SMA, sensorimotor cortex, and motor striatum.
• Model-driven analysis revealed that tSMS-induced striatal modulation is primarily driven by changes in corticostriatal shared activity.

Conclusions:

• Corticostriatal activity can be effectively targeted, monitored, and modulated noninvasively in humans using tSMS combined with fMRI.
• The ISAAC framework provides a robust method for analyzing complex brain activity and connectivity.
• This approach holds potential for developing novel nonpharmacological treatments for brain disorders affecting the corticostriatal system.