"Although brain oscillations involving the basal ganglia (BG) have been the target of extensive research, the main focus lies disproportionally on oscillations generated within the BG circuit rather than other sources, such as cortical areas. We remedy this here by investigating the influence of various cortical frequency bands on the intrinsic effective connectivity of the BG, as well as the role of the latter in regulating cortical behaviour. To do this, we construct a detailed neural model of the complete BG circuit based on fine-tuned spiking neurons, with both electrical and chemical synapses as well as short-term plasticity between structures. As a measure of effective connectivity, we estimate information transfer between nuclei by means of transfer entropy. Our model successfully reproduces firing and oscillatory behaviour found in both the healthy and Parkinsonian BG. We found that, indeed, effective connectivity changes dramatically for different cortical frequency bands and phase offsets, which are able to modulate (or even block) information flow in the three major BG pathways. ..."
Model Type: Realistic Network
Cell Type(s): Subthalamic nucleus principal GABA cell; Globus pallidus principal GABA cell; Substantia nigra pars reticulata principal GABA cell; Subthalamus nucleus projection neuron; Globus pallidus neuron
Simulation Environment: Brian
Implementer(s): Fountas, Zafeirios [zfountas at imperial.ac.uk]