Chapman B, Stryker M P
W. M. Keck Foundation Center for Integrative Neuroscience, Department of Physiology, University of California, San Francisco 94143-0444.
J Neurosci. 1993 Dec;13(12):5251-62. doi: 10.1523/JNEUROSCI.13-12-05251.1993.
The orientation selectivity of cells in ferret primary visual cortex was studied during normal development and in animals deprived of vision or of visual cortical activity. In normal animals from the age when visual responses were first recorded (postnatal day 23) through postnatal week 5, only about 25% of cells showed orientation-selective responses. By postnatal week 7, cortical responses had matured to an adult-like state, with approximately 75% of cells clearly selective for orientation. This development of orientation selectivity was not merely a reflection of the development of cortical cell responsiveness: at all ages studied, there was no correlation between responsiveness and selectivity. Infusion of TTX into visual cortex to silence neuronal activity completely blocked the maturation of orientation selectivity. Visual deprivation by bilateral lid suture impaired but did not completely block the normal development of orientation selectivity. We conclude that the maturation of orientation-selective responses in ferret primary visual cortex requires cortical neuronal activity, and that normal development requires visually driven activity.
在雪貂初级视觉皮层正常发育过程中以及在视觉剥夺或视觉皮层活动被剥夺的动物中，研究了细胞的方向选择性。在正常动物中，从首次记录到视觉反应的年龄（出生后第23天）到出生后第5周，只有约25%的细胞表现出方向选择性反应。到出生后第7周，皮层反应已成熟到类似成年动物的状态，约75%的细胞对方向有明显的选择性。方向选择性的这种发育不仅仅是皮层细胞反应性发育的反映：在所有研究的年龄阶段，反应性和选择性之间均无相关性。向视觉皮层注入TTX使神经元活动完全沉默，这完全阻断了方向选择性的成熟。双侧眼睑缝合造成的视觉剥夺损害了但并未完全阻断方向选择性的正常发育。我们得出结论，雪貂初级视觉皮层中方向选择性反应的成熟需要皮层神经元活动，而正常发育需要视觉驱动的活动。
