A large-scale model of the cerebellar cortex using PGENESIS

In an investigation into the transformation of mossy fiber input to Purkinj e cell output in the cerebellar cortex, we have developed a network model i ncluding a sophisticated compartmental model of the Purkinje cell. Analysis and simulations demonstrated the need to include a large number of paralle l fibers (244000) to obtain realistic Purkinje cell firing patterns for ran dom mossy fiber input. Using smaller numbers of parallel fiber inputs resul ted in unrealistic Purkinje cell spiking characterized by spontaneous dendr itic calcium spikes. Because the scale required is beyond workstation capab ilites, we used a 128-processor Gray T3E running PGENESIS. This size networ k could produce realistic spiking patterns provided the stellate cell inhib ition was tuned carefully. (C) 2000 Elsevier Science B.V. All rights reserv ed.