A model of pathological oscillations in the basal ganglia and deep brain stimulation in parkinson’s disease

A model of pathological oscillatory activity within the basal ganglia in Parkinson´s disease is presented. Synchronous oscillatory activity of the subthalamic nucleus (STN) and globus pallidus external (GPe) is simulated at both the parkinsonian tremor (3-9) Hz and beta (15-30) Hz frequencies. The model extends previous models to incorporate cortical inputs to the subthalamic nucleus through the `hyperdirect´ pathway, changes in coupling between STN neurons due to dopamine depletion and the plateau potential generating capacity of STN neurons. The effect of deep brain stimulation (DBS) across a range of frequencies on the oscillatory activity is examined. High frequency DBS attenuates synchronous oscillatory activity within the STN-GPe network at both the tremor and beta frequencies. The efficacy of the DBS input in quenching the pathological oscillations is shown to vary systematically with the frequency, pulse width and amplitude of the applied stimulus.