[2 types of eye movements during electric stimulation of the rostral and caudal portions of the medial frontal "oculomotor" zone in the cat]

Abstract

Electrical stimulation of mesial wall of the hemisphere with a portion of the lower lip of the cruciate sulcus in awake alert cat elicited two types of eye movements. Stimulation of the caudal part of this area evoked contraversive conjugate saccadic eye movements whose directions and amplitudes were independent of the position of the eye in the orbit. Stimulation of the rostral part evoked conjugate eye movements in the central position (centring saccades). The topographical distribution of evoked eye movement directions in the caudal part of the studied area led to the conclusion about its retinotopic organization where vertical saccades (up and down), evoked at the lateral side of the lower lip of the cruciate sulcus, marked the place of projection of the vertical meridian. The repeated appearance of vertical saccades from the mesial wall of the hemisphere suggests existence of more then one retinotopic area in this part of the brain.