DYNAMIC CHANGES IN RECEPTIVE-FIELD SIZE IN CAT PRIMARY VISUAL-CORTEX
DYNAMIC CHANGES IN RECEPTIVE-FIELD SIZE IN CAT PRIMARY VISUAL-CORTEX
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DOI：
10.1073/pnas.89.17.8366
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发表时间：
1992-09-01
影响因子：
11.1
通讯作者：
GILBERT, CD
中科院分区：
文献类型：
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作者：
PETTET, MW;GILBERT, CD
在局灶性视网膜损伤后，即使视网膜损伤仅限于感光层，初级视皮层的感受野（RF）也会立即显著扩大。这些变化的时间过程表明，仅仅是在射频附近缺乏刺激，伴随着周围区域的刺激，就会导致射频扩张。当从猫17区的单个细胞记录时，我们用视野中的移动线模式模拟这种刺激模式，掩盖覆盖记录细胞RF的区域，从而产生“人工暗点”。“在几乎等于10分钟的时间内，这种掩蔽导致RF面积平均扩大5倍。刺激RF中心导致场的大小崩溃，恢复到接近其原始程度;用掩蔽的刺激进行再调节导致RF再扩张。需要在周围区域进行刺激以发生射频扩展-在暴露于空白屏幕期间几乎没有看到扩展。我们建议，扩展可能占视觉错觉，如知觉填充稳定的图像和虚幻的轮廓，并可能构成前驱症状的视网膜病变后改变皮层地形。这些发现支持了这样一种观点，即即使在成年动物中，RF也是动态的，能够被感觉环境改变。
Immediately after focal retinal lesions, receptive fields (RFs) in primary visual cortex expand considerably, even when the retinal damage is limited to the photoreceptor layer. The time course of these changes suggests that mere lack of stimulation in the vicinity of the RF accompanied by stimulation in the surrounding region causes the RF expansion. While recording from single cells in cat area 17, we simulated this pattern of stimulation with a pattern of moving lines in the visual field, masking out an area covering the RF of the recorded cell, thereby producing an "artificial scotoma." Over almost-equal-to 10 min this masking resulted in a 5-fold average expansion in RF area. Stimulating the RF center caused the field to collapse in size, returning to near its original extent; reconditioning with the masked stimulus led to RF reexpansion. Stimulation in the surrounding region was required for the RF expansion to occur-little expansion was seen during exposure to a blank screen. We propose that the expansion may account for visual illusions, such as perceptual fill-in of stabilized images and illusory contours and may constitute the prodrome of altered cortical topography after retinal lesions. These findings support the idea that even in adult animals RFs are dynamic, capable of being altered by the sensory context.