Retinal and Cortical Changes in the Visual System of Pattern-Deprived Rats
Substantial electrophysiological changes in the visual cortex and lateral geniculate nucleus of cats result from unilateral pattern deprivation. The question arises whether these changes are secondary to those occurring in the retina. When retinal responses (ERG’s) of visually deprived cats were examined, a diminution of the b-wave of the deprived eye was found in some studies. Baxter and Riesen (1961) showed a rapid recovery of the b-wave during exposure to normal light conditions in cats that had been dark-reared for 12 months. Similar depression and recovery of the ERG b-wave were obtained with adult cats visually deprived for a period of a few days to several weeks (Cornwell & Sharpless, 1968; Ganz et al., 1968; Hamasaki & Pollack, 1972). Also, Hamasaki & Flynn (1973) found that children monocularly deprived for 1–6 months by eye patching showed a depression of the ERG followed by recovery after removal of the patch. No effects were observed in other studies in the cat (Wiesel & Hubel, 1963; Sherman & Stone, 1973) or in the monkey (von Noorden et al., 1970). These inconsistencies led us to examine the effects of long term pattern deprivation on the rat retina. The rat was chosen as the experimental animal partially for technical reasons and because it is representative of a simple mammalian retina.
KeywordsVisual Cortex Receptive Field Lateral Geniculate Nucleus Visual Deprivation Receptive Field Size
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