Previous work has shown that optical imaging can be used to visualize maps of ocular dominance, orientation, and retinotopy in macaque striate cortex and to follow their development in young animals. In addition to verifying the existence of many adult organizations in infants, these studies also revealed several unexpected developmental reorganizations, namely 1) that neonatal V1 grows anisotropically, perpendicular to ocular dominance columns, 2) that the resulting distortions may generate anisotropic magnification factors in adults, and 3) that ocular dominance and orientation patterns may drift in relation to each other (and anatomical landmarks), as the cortex expands. In order to investigate these possibilities further, we proposed longitudinal experiments in single animals, to obtain images of ocular dominance, orientation, and position (magnification) repeatedly from the same regions. Fully analyzed data from our first experimental animals now show that cortex expands anisotropically, perpendicular to OD columns, during development (as expected), and several observations that were not expected though they are consistent with other findings. These are 1) that neonatal V1 undergoes shearing (twisting) during development, and 2) that new features (e.g., OD bifurcations) may be added in some regions as the cortical surface expands. Since the approach clearly works and the findings are clearly relevant to developmental pathologies in humans (e.g., amblyopia, stereoblindness, etc.), funds are requested to continue these efforts in more animals, to explore these changes at more eccentricities and in greater detail.
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