Subthalamic-pallidal interactions are critical in determining normal and abnormal functioning of the basal ganglia.
The subthalamic nucleus (STN) and external globus pallidus (GP) form a recurrent excitatory-inhibitory interaction within the basal ganglia. Through a computational model of these interactions we show that, under the influence of appropriate external input, the two nuclei can be switched between states of high and low activity or can generate oscillations consisting of bursts of high-frequency activity repeated at a low rate. It is further demonstrated from the model that the generation of the repetitive bursting behaviour is favoured by increased inhibition of the GP, which is a condition indicated in Parkinson's disease. Paradoxically, increased striatal inhibition of the GP is predicted to cause an increase rather than a decrease in its mean firing rate. These behaviours, arising from a biologically inspired computational model of the STN-GP interaction, have important consequences for basal ganglia function and dysfunction.
Gillies
Andrew
A
Institute for Adaptive and Neural Computation, University of Edinburgh, 5 Forrest Hill, Edinburgh EH1 2QL, UK. a.gillies@anc.ed.ac.uk
Willshaw
David
D
Li
Zhaoping
Z
D001479:Basal Ganglia / Q000502:physiology*; D003198:Computer Simulation; D025461:Feedback, Physiological; D005917:Globus Pallidus / Q000502:physiology*; D006801:Humans; D008959:Models, Neurological; D009434:Neural Pathways / Q000502:physiology; D010300:Parkinson Disease / Q000503:physiopathology; D020531:Subthalamic Nucleus / Q000502:physiology*