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Fig. 5.2. Normal vs. strabismic cat ocular dominance maps and lateral connections. These plots show corresponding 5 mm × 5 mm portions of the V1 ocular dominance maps from a normal cat (a) and from a cat raised with artificial strabismus (b). The maps were obtained using anatomical tracers, which result in categorical eye preferences (represented by light and dark areas instead of gray scale as in Figure 2.5). Both maps contain patches specific to each eye, but the patches are larger and more sharply delineated in the strabismic case. In (a), the green star indicates where fluorescent tracer was injected, and the green dots show where lateral retrograde transport took them. The lateral connection patterns do not significantly depend on the ocular dominance patterns. In (b), the red star and the green star (pointed by the arrow) mark two separate injection sites in right-eye columns (black). The lateral connections preferentially target neurons with the same eye preference (black patches, marked with red and green dots), and avoid neurons with the opposite eye preference (white). Each injection killed the nearby cells as a side effect, and therefore the ocular dominance and connection patterns are not visible in the areas surrounding the injections. Those areas are likely to be strongly connected to the neurons at the injection site. Detail of a figure by Löwel and Singer (1992), reprinted with permission, copyright 1992 by the American Association for the Advancement of Science.