A large-scale model of the cerebellar cortex using PGENESIS

In an investigation into the transformation of mossy ber input to Purkinje cell output in the cerebellar cortex, we have developed a network model including a sophisticated compartmental model of the Purkinje cell. Analysis and simulations demonstrated the need to include a large number of parallel bers (244,000) to obtain realistic Purkinje cell ring patterns for random mossy ber input. Using smaller numbers of parallel ber inputs resulted in unrealistic Purkinje cell spiking characterized by spontaneous dendritic calcium spikes. Because the scale required is beyond workstation capabilites, we used a 128-processor Cray T3E running PGENESIS. This size network could produce realistic spiking patterns provided the stellate cell inhibition was tuned carefully.