The Retina as a Model of the Brain
Because of its distance from the brain, the retina can be considered a sense organ at the same level as that of other sense organs like the ear, the muscle stretch receptor, or the pressure sensitive receptor of the skin. This view, however, would be a gross oversimplification, since the retina because of its layered structure closely resembles in its organisation the cerebral cortex itself. In a normal penetration of the retina you will record from up to five types of cells all of which will have their receptive field located in the same region in space. From this fact, which we all considered obvious in the retina, could we have predicted finding similar results in a normal penetration of the visual cortex and thus predicted the “columnar organisation” found by Hubel and Wiesel? Certainly not, if you consider the retina only as a sense organ; perhaps, if you think of it as a model of the brain.
KeywordsGanglion Cell Receptive Field Sense Organ Horizontal Cell Spike Discharge
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