A neuro-computational model of pallidal vs. subthalamic deep brain stimulation effect on synchronization at tremor frequency in Parkinson's disease

Parkinson's disease is a neurodegenerative disorder, associated with different motor symptoms including tremor, akinesia, bradykinesia, rigidity as well as gait and speech impairments. Previously, we have presented a neurobiologically detailed neuro-computational model simulating the basal ganglia functioning as well as the effects of subthalamic deep brain stimulation on action section (Mandali A, Chakravarthy VS, Rajan R, Sarma S, Kishore A, Front Physiol 7:585, 2016; Mandali A, Rengaswamy M, Chakravarthy S, Moustafa AA, Front Neurosci 9:191, 2015). In the current study, we extend our prior model by including thalamic and cortical neurons and compare the effect of subthalamic and pallidal stimulation on tremor in terms of oscillations within STN and GPi and subsequently their effect on the cortex. In agreement with existing experimental studies, our model shows that subthalamic stimulation is more effective at reducing the tremor power than the pallidal stimulation. Our model provides a mechanistic explanation for such comparative results.