A MASSIVELY CONNECTED SUBTHALAMIC NUCLEUS LEADS TO THE GENERATION OF WIDESPREAD PULSES

A composite model of the subthalamic nucleus is developed from physiol ogical and anatomical considerations. First, study of a geometric mode l of the anatomical arrangements of projection neurons within the nucl eus indicates that they form a massively connected network. Second, gi ven the excitatory nature of these neurons, their threshold and peak f iring rates, a simple model of neuron responses reveals that large reg ions of this highly interconnected nucleus can respond to excitatory i nput in the form of a widespread uniform pulse. Such widespread pulses of activity may act as a braking signal that resets the major basal g anglia output nuclei.