Colliculoreticular Organization in the Oculomotor System

This chapter summarizes saccadic eye movement-related discharge in superior colliculus neurons and in median pontomedullary reticular formation (RF) neurons and reviews the organization of colliculoreticular pathways, particularly with a view towards clarifying the mechanisms involved in controlling saccades in primates.

Abstract

This chapter summarizes saccadic eye movement-related discharge in superior colliculus (SC) neurons and in median pontomedullary reticular formation (RF) neurons and reviews the organization of colliculoreticular pathways, particularly with a view towards clarifying the mechanisms involved in controlling saccadic eye movements in primates. New data on the functional type of SC input to the RF are presented. A new interpretation is placed on the possible role played in saccadic generation by a class of neurons called quasi-visual cells. Saccade-related discharge of brain stem reticular formation neurons is discussed and comparisons are made between presaccadic activity in neurons in SC and RF. Studies showing the existence and nature of synaptic input from the SC to specific functional types of RF cells are reviewed and new preliminary results indicating the functionally identified type of SC neuron supplying at least a portion of these connections are shown. The possible role played by the neurons and synaptic connections described in these two anatomic structures is hypothesized in the form of saccadic control model.