Animal models for the optokinetic system of the human

Abstract

We compare the neuronal and behavioural consequences of abnormal visual experience during early infancy for the optokinetic system of cat and monkey with the neuroopthalmological results in man. Optokinetic eye movements were recorded with the search coil method and electrooculography. In addition, the response properties of single neurons in the visual cortex and pretectum of anesthetized and paralyzed cats and monkeys were determined in electrophysiological experiments. Our data show that monocular deprivation and strabismus lead to an increase of asymmetry of monocular optokinetic nystagmus and a decrease in gain of slow phase optokinetic eye movements during monocular stimulation as well as to a significant decrease of binocular convergence in the oculomotor system of both cat and monkey. Although these changes are basically similar in both species they are not identical. These differential effects may be explained by structural differences. Assuming a similar neuronal substrate for the optokinetic system in all primates the monkey represents a more suitable animal model for the human visual system than the cat.