Exercise-Induced Modulation of Subthalamic Activity and Intra-Nuclear Connectivity

Area of Science:

• Neuroscience
• Movement Disorders
• Rehabilitation

Background:

• Parkinson's disease (PD) treatments include medications, deep brain stimulation (DBS), and exercise.
• Levodopa and DBS effects on the subthalamic nucleus (STN) are known, but exercise's impact is unclear.

Purpose of the Study:

• Investigate acute and long-term effects of a monthlong motorized cycling intervention on STN activity in PD patients.
• Clarify how exercise modulates STN circuitry, potentially revealing shared neuromodulatory mechanisms with other PD treatments.

Main Methods:

• Used local field potential (LFP) recordings from 29 electrodes in 18 STNs across nine PD patients.
• Analyzed LFP features to assess changes in STN activity over a month of daily motorized cycling.
• Quantified dorsal-ventral STN coupling using imaginary part of coherency (iCOH) and phase slope index (PSI).

Main Results:

• Long-term cycling produced progressive increases in total LFP power in the dorsal STN, driven by the aperiodic background.
• The ventral STN showed no significant change in LFP power over the same interval.
• Increased iCOH in the 24-29 Hz range suggested a shared upstream driver, confirmed by a statistical SSTr framework.

Conclusions:

• Motorized cycling progressively modulates dorsal STN activity, distinct from ventral STN changes.
• Exercise engages neuromodulatory mechanisms overlapping with, but not identical to, levodopa or STN-DBS.
• Evidence suggests a shared upstream driver influences both dorsal and ventral STN regions during exercise in PD.