Spitzer H, Hochstein S
Isr J Med Sci. 1987 Jan-Feb;23(1-2):69-74.
Retinal ganglion and lateral geniculate cells of the primary visual pathway may be categorized as X or Y according to their spatial linearity summation properties. In particular, Y cell spatial-frequency transfer functions have a distinctive spatial--linearity signature. Their receptive fields comprise a temporally and spatially linear mechanism (center plus antagonistic surround) that responds to relatively low spatial frequency stimuli, and a temporally nonlinear mechanism, coextensive with the linear mechanism, that--though broad in extent--responds best to high spatial-frequency stimuli. This component exhibits spatially nonlinear properties. We looked for this Y cell signature in cat visual cortical cells. If the predominant excitatory input to a certain type of cortical cell were from lateral geniculate nucleus (LGN) Y cells, we would expect to find the Y cell signature underlying the cortical cell transfer function. However, we have not found this Y cell signature in any of the cortical cell studied, and in particular not in the nonlinear complex cells. This would suggest that cortical spatial summation nonlinearities are not functionally derived from input Y cell nonlinearities.
初级视觉通路的视网膜神经节细胞和外侧膝状体细胞可根据其空间线性总和特性分为X或Y细胞。特别是，Y细胞的空间频率传递函数具有独特的空间线性特征。它们的感受野包括一个对相对低空间频率刺激做出反应的时间和空间线性机制（中心加拮抗周边），以及一个与线性机制共存的时间非线性机制，尽管范围广泛，但对高空间频率刺激反应最佳。该成分表现出空间非线性特性。我们在猫视觉皮层细胞中寻找这种Y细胞特征。如果某类皮层细胞的主要兴奋性输入来自外侧膝状体核（LGN）的Y细胞，我们预计会在皮层细胞传递函数中找到Y细胞特征。然而，我们在所研究的任何皮层细胞中都未发现这种Y细胞特征，尤其是在非线性复合细胞中。这表明皮层空间总和非线性并非在功能上源自输入Y细胞的非线性。
