Fig. 1.

Optical imaging of intrinsic signals from the visual cortex of young cats at postnatal day 21 (P21) (A), P14 (B), and P8 (C). Responses through the contralateral eye are shown as darker areas. Distinct ocular dominance columns (light and dark patches) are present at P21. In cats a week younger (P14), eye-specific responses (light areas are ipsilateral eye patches) are emerging, although the cortex is dominated by responses through the contralateral eye (dark areas). No ocular dominance pattern is visible in a P8 cat (C), and the response is biased toward the contralateral eye (dark). Gray response scale applies to all images, which are not smoothed. Scale bar = 500 μm.