Our main objective is to understand the central nervous system of higher mammals, its normal function and anatomy, its development, and its response to postnatal distortion of experience. Our work involves predominantly the visual system of cats and monkeys, at the level of the visual cortex. We study function by stimulating with natural stimulation of the retinas, and record from single cells with extracellular microelectrodes. Anatomical studies use mainly the Nauta-Fink-Heimer silver degeneration method, autoradiography following axonal transport, desoxyglucose and horseradish peroxidase retrograde transport, and electron microscopy. Visual deprivation studies involve mainly eye closures and artificial strabismus. Development work is on Siamese cats and various forms of central nervous mutant mice.