Murphy K M, Mitchell D E
Nature. 1986;323(6088):536-8. doi: 10.1038/323536a0.
The majority of neurones in the visual cortex of both adult cats and kittens can be excited by visual stimulation of either eye. Nevertheless, if one eye is deprived of patterned vision early in life, most cortical cells can only be activated by visual stimuli presented to the nondeprived eye and behaviourally the deprived eye is apparently useless. Although the consequences of monocular deprivation can be severe, they can in many circumstances be rapidly reversed with the early implementation of reverse occlusion which forces the use of the initially deprived eye. However, by itself reverse occlusion does not restore a normal distribution of cortical ocular dominance and only promotes visual recovery in one eye. In an effort to find a procedure that might restore good binocular vision, we have examined the effects on acuity and cortical ocular dominance of a short, but physiologically optimal period of reverse occlusion, followed by a period of binocular vision beginning at 7.5 weeks of age. Surprisingly, despite the early introduction of binocular vision, both eyes attained acuities that were only approximately 1/3 of normal acuity levels. Despite the severe bilateral amblyopia, cortical ocular dominance appeared similar to that of normal cats. This is the first demonstration of severe bilateral amblyopia following consecutive periods of monocular occlusion.
成年猫和幼猫视觉皮层中的大多数神经元都能被任何一只眼睛的视觉刺激所兴奋。然而，如果在生命早期剥夺一只眼睛的模式视觉，大多数皮层细胞只能被呈现给未被剥夺眼睛的视觉刺激所激活，并且从行为上看，被剥夺的眼睛显然是无用的。尽管单眼剥夺的后果可能很严重，但在许多情况下，通过早期实施反向遮盖（即迫使使用最初被剥夺的眼睛），这些后果可以迅速逆转。然而，仅靠反向遮盖本身并不能恢复皮层眼优势的正常分布，而只能促进一只眼睛的视觉恢复。为了找到一种可能恢复良好双眼视觉的方法，我们研究了一段短暂但生理上最佳的反向遮盖期对视力和皮层眼优势的影响，随后是从7.5周龄开始的双眼视觉期。令人惊讶的是，尽管早期引入了双眼视觉，但两只眼睛的视力仅达到正常视力水平的约1/3。尽管存在严重的双侧弱视，但皮层眼优势看起来与正常猫相似。这是连续单眼遮盖后出现严重双侧弱视的首次证明。
