Receptive field structure of H1 horizontal cells in macaque monkey retina.
Receptive field structure of H1 horizontal cells in macaque monkey retina.
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DOI：
10.1167/2.4.1
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发表时间：
2002-01-01
影响因子：
1.8
通讯作者：
Dacey, Dennis M
中科院分区：
文献类型：
--
作者：
Packer, Orin S;Dacey, Dennis M
灵长类动物视网膜的神经节细胞具有中心环绕的感受野。调节线性环绕电路的一个强有力的候选者是从 H1 水平细胞到锥蒂的负反馈。我们使用正弦光栅、斑点和环测量了体外猕猴视网膜中 H1 细胞感受野的空间特性。空间调谐曲线的形状从平滑的低通到明显的凹口不等。大约 80% 的细胞的调谐曲线可以通过两个指数之和很好地描述，在宽浅的裙边上叠加一个突出的中心峰。组合感受野的平均直径随着偏心率的增加而减小，从 11 毫米时的 309 微米减小到 4 毫米时的 122 微米。我们认为，强的窄视野反映了来自树突树上的锥体的直接突触输入，而弱的宽视野则反映了来自邻近 H1 细胞的耦合输入。那些不能很好地拟合指数总和的单元格的调谐曲线在较高空间频率处具有额外的峰值，这可能是由于锥体 H1 网络中的欠采样造成的。与其他脊椎动物不同，猕猴 H1 网络的耦合程度较低，感受野较小，并且没有功能可塑性。猕猴 H1 的感受野小得出奇，这表明电耦合大大减少。由于 H1 感受野中心仅从耦合场获得其总响应的一小部分，因此最小感受野的直径与树突树的直径相似。它们可能小到足以形成中心凹侏儒细胞的周围。 H1 网络与频谱对抗的混合环绕模型兼容。
The ganglion cells of primate retina have center-surround receptive fields. A strong candidate for mediating linear surround circuitry is negative feedback from the H1 horizontal cell onto the cone pedicle. We measured the spatial properties of H1 cell receptive fields in the in vitro macaque monkey retina using sinusoidal gratings, spots, and annuli. Spatial tuning curves ranged in shape from smoothly low pass to prominently notched. The tuning curves of approximately 80% of cells could be well described by a sum of two exponentials, giving a prominent central peak superimposed on a broad shallow skirt. The mean diameter of the combined receptive field decreased with eccentricity from 309 micro m at 11 mm to 122 micro m at 4 mm. We propose that the strong narrow field reflects direct synaptic input from the cones overlying the dendritic tree whereas the weak wide field reflects coupled inputs from neighboring H1 cells. Those cells not well fit by a sum of exponentials had tuning curves with additional peaks at higher spatial frequencies that were likely due to undersampling in the cone-H1 network. Unlike other vertebrates, the macaque H1 network is less strongly coupled, has smaller receptive fields, and shows no functional plasticity. Macaque H1 receptive fields are surprisingly small, suggesting a great reduction in electrical coupling. Because the center of the H1 receptive field gets only a small percentage of its total response from the coupled field, the smallest receptive fields are similar in diameter to the dendritic trees. They are probably small enough to form the surrounds of foveal midget cells. The H1 network is compatible with a mixed-surround model of spectral opponency.