Toward a Spiking-Neuron Model of the Oculomotor System

We present a physiologically plausible spiking neuron-level model of the superior colliculus as part of the saccade-generating visual system. Two major features of the area are the bursting behavior of its output neurons that drive eye movements, and the spreading neuron activation in the intermediate layer during a saccade. We show that the bursting activity profile that drives the main sequence behavior of saccadic eye movements can be generated by a combination of NMDA and cholinergic receptors driven by a local circuit. We also show how the long-range spreading activation can occur, and propose that the functional role for this mechanism is to track the general activity level and trigger a system-wide reset at the end of a saccade.