Modeling effect of GABAergic current in a basal ganglia computational model.

Electrical high frequency stimulation (HFS) of deep brain regions is a method shown to be clinically effective in different types of movement and neurological disorders. In order to shed light on its mode of action a computational model of the basal ganglia network coupled the HFS as injection current into the cells of the subthalamic nucleus (STN). Its overall increased activity rendered a faithful transmission of sensorimotor input through thalamo-cortical relay cells possible. Our contribution uses this model by Rubin and Terman (J Comput Neurosci, 16, 211-223, 2004) as a starting point and integrates recent findings on the importance of the extracellular concentrations of the inhibiting neurotransmitter GABA. We are able to show in this computational study that besides electrical stimulation a high concentration of GABA and its resulting conductivity in STN cells is able to re-establish faithful thalamocortical relaying, which otherwise broke down in the simulated parkinsonian state.