On and off domains of geniculate afferents in cat primary visual cortex
On and off domains of geniculate afferents in cat primary visual cortex
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DOI：
10.1038/nn2029
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发表时间：
2008-01-01
影响因子：
25
通讯作者：
Alonso, Jose-Manuel
中科院分区：
文献类型：
--
作者：
Jin, Jianzhong Z.;Weng, Chong;Alonso, Jose-Manuel
中心和偏离中心的膝状体传入形成了视觉处理的两个主要通道，它们被认为会聚在初级视觉皮层中。然而，当在白色背景中测试时，具有严重降低的开启响应的人可以具有正常的视敏度，这表明在某些条件下，关闭通道可以相对独立于开启通道起作用。与此功能的独立性的渠道，我们在这里证明，上和偏离中心膝状体传入隔离在不同的领域的猫初级视觉皮层和关闭反应占主导地位的中央区域的皮质表示。平均而言，70%的膝状体传入会聚在同一皮质域的感受野相同的对比极性。此外，偏离中心的传入纤维在皮质中央区的代表中占主导地位，但在丘脑中却不占主导地位，这表明中心和偏离中心的传入纤维在数量上是平衡的，但在它们覆盖的皮质区域的数量上却不平衡。
On- and off-center geniculate afferents form two major channels of visual processing that are thought to converge in the primary visual cortex. However, humans with severely reduced on responses can have normal visual acuity when tested in a white background, which indicates that off channels can function relatively independently from on channels under certain conditions. Consistent with this functional independence of channels, we demonstrate here that on- and off-center geniculate afferents segregate in different domains of the cat primary visual cortex and that off responses dominate the cortical representation of the area centralis. On average, 70% of the geniculate afferents converging at the same cortical domain had receptive fields of the same contrast polarity. Moreover, off-center afferents dominated the representation of the area centralis in the cortex, but not in the thalamus, indicating that on- and off-center afferents are balanced in number, but not in the amount of cortical territory that they cover.