Increased receptive field size in the surround of chronic lesions in the adult cat visual cortex
Increased receptive field size in the surround of chronic lesions in the adult cat visual cortex
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DOI：
10.1093/cercor/9.2.101
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发表时间：
1999-03-01
期刊：
影响因子：
3.7
通讯作者：
Schweigart, G
中科院分区：
文献类型：
--
作者：
Eysel, UT;Schweigart, G
视觉皮质损伤破坏特定视网膜区域膝状体皮质纤维的靶细胞。我们研究了成年猫视皮质局灶性鹅掌酸损伤前、损伤后2天和2个月后视皮层细胞的感受野，发现在慢性而不是急性和亚急性兴奋性损伤的周围环境中有感受野可塑性的迹象。在亚急性状态(损伤后头两天)，损伤边缘细胞的感受野大小变小或保持不变。2个月后重新定位皮质感受野，发现在病变边缘有许多细胞的感受野扩大了许多倍。感受野增大的细胞表现出与正常细胞一样的定向和方向选择性。大小的增加似乎不是专门针对暗点；然而，扩大的感受野可以减少皮质暗点的范围，因为以前视野的无反应区域激活了病变边缘的皮质细胞。这种晚期感受野的可塑性可能是在视皮层损害患者中观察到的皮质暗点填充的一种机制。
Visual cortical lesions destroy the target cells for geniculocortical fibers from a certain retinotopic region. This leads to a cortical scotoma, We have investigated the receptive fields of cells in the visual cortex before, 2 days and 2 months after focal ibotenic acid lesions in the adult cat visual cortex and have found signs of receptive field plasticity in the surroundings of the chronic but not the acute and subacute excitotoxic lesions. In the subacute state (first two days post lesion) receptive field sizes of cells at the border of the lesion were reduced in size or remained unchanged. Remapping of cortical receptive fields 2 months later revealed a number of cells with multifold enlarged receptive fields at the border of the lesion. The cells with enlarged receptive fields displayed orientation and direction selectivity like normal cells. The size increase appeared not specifically directed towards the scotoma; however, the enlarged receptive fields can reduce the extent of a cortical scotoma, since previously unresponsive regions of the visual field activate cortical cells at the border of the lesion. This late receptive field plasticity could serve as a mechanism for the filling-in of cortical scotomata observed in patients with visual cortex lesions.