Contrast-dependent and contrast-independent spatial summation of primary visual cortical neurons of the cat.
Contrast-dependent and contrast-independent spatial summation of primary visual cortical neurons of the cat.
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DOI：
10.1093/cercor/bhm057
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发表时间：
2008-02
期刊：
影响因子：
3.7
通讯作者：
Xuemei Song;Chaoyi Li
中科院分区：
文献类型：
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作者：
Xuemei Song;Chaoyi Li
最近的研究表明，经典感受野（CRF）的大小和V1神经元的空间总和的程度依赖于刺激对比度。我们重新检查了48 V1神经元在猫的这些属性，发现所有的细胞有一个恒定的CRF大小，而它们的空间总和属性可以是对比度依赖（CD）或对比度无关（CID）。在29个CD细胞中，17个在低对比度下表现出易化求和（10%），但在高对比度下表现出抑制性求和（80%）;另外12个在低对比度下表现出弱抑制性求和，而在高对比度下抑制强度显著增加。19个CID细胞在低对比度和高对比度下显示相似的易化（CIDf）或抑制（CID）总和，形状和/或峰位置无变化。我们成功地用生物胞素标记了11个CD细胞和10个CID细胞。形态学结果表明，标记的CD细胞均为锥体细胞，而标记的CID细胞均为非锥体细胞，其中CIDf细胞为棘星状细胞，CID细胞为光滑中间神经元。因此，在锥体细胞和非锥体细胞的总和特性之间，以及在光滑的非锥体细胞和多刺的非锥体细胞之间，存在着全局性的区别。
Recent studies have reported that the size of the classical receptive field (CRF) and the extent of spatial summation of V1 neurons depend on stimulus contrast. We reexamined these properties for 48 V1 neurons in the cat and found that all the cells had a constant CRF size, whereas their spatial summation properties can be contrast dependent (CD) or contrast independent (CID). Of the 29 CD cells, 17 showed facilitatory summation at low contrast (10%), but suppressive summation at high contrast (80%); the other 12 showed weak suppressive summation at low contrast, whereas the strength of suppression increased significantly at high contrast. The 19 CID cells showed similar facilitative (CIDf) or suppressive (CIDs) summation at low and high contrast, without changes in shape and/or peak location. We successfully labeled 11 CD cells and 10 CID cells with biocytin. The morphological results demonstrated that all the labeled CD cells were pyramidal cells, whereas all labeled CID cells were nonpyramidal cells, in which the CIDf cells were spiny stellates and the CIDs cells, smooth interneurons. There is thus a global distinction between summation properties of pyramidal and nonpyramidal cells, and between the smooth and spiny nonpyramidal cells as well.