Neural control of saccadic eye movements.

One of the major functions of the central nervous system is the generation of movement in response to sensory stimulation. The visual guidance of saccadic eye movement represents one form of sensory-to-motor transformation that has contributed significantly to our understanding of motor control and sensorimotor processing at large. The neural circuitry controlling saccadic eye movements is now understood at a level that is sufficient to link the specific roles of a number of saccade-related cortical and subcortical areas. In this chapter, we review the main subcortical areas for controlling saccades, concentrating mostly on the role of the posterior cerebellar vermis (PV), with the dorsal pontine nuclei and the nucleus reticularis tegmenti pontis as the major gateway to the PV and the fastigial nucleus as the link between the PV and the brainstem saccade generator. We argue that the PV is the key structure enabling saccadic learning and that this contribution is based on the control of saccade duration by a PV Purkinje cell population signal.