Transcranial alternating current stimulation can disrupt or reestablish neural entrainment in parkinsonian motor cortex.

BACKGROUND

In Parkinson's disease, motor network electrophysiology frequently exhibits excessive beta oscillations. The cornerstone of therapeutic efficacy lies in the ability to modulate these pathological oscillations. Transcranial alternating current stimulation (tACS), a non-invasive method that applies oscillating electric fields to modulate ongoing brain activity, offers a promising approach.

OBJECTIVE

The objective of the manuscript is to investigate the dose-dependent effects of tACS on motor network cortical neurons in a Parkinson's disease model.

METHODS

We recorded neuronal spike activity in the motor cortex in parkinsonian non-human primates during tACS to determine how stimulation-induced electric fields affect spike timing.

RESULTS

Strong electric fields entrained neural activity at the stimulation frequency but altered the preferred spiking phase. Conversely, weak fields disrupted beta-band synchronization by modulating spike timing and phase preference. Frequency-matched stimulation significantly enhanced entrainment when aligned with endogenous oscillatory activity.

CONCLUSION

Thus, with appropriately chosen stimulation parameters, tACS exhibits significant potential for controlling and modulating pathological oscillatory patterns that are characteristic of many neurological disorders.