A unique morphological subtype of horizontal cell in the rabbit retina with orientation-sensitive response properties.
A unique morphological subtype of horizontal cell in the rabbit retina with orientation-sensitive response properties.
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兔子视网膜中水平细胞的独特形态亚型，具有方向敏感响应特性。
DOI：
10.1002/cne.903200105
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Bloomfield,SA
中科院分区：
文献类型：
--
作者：
Bloomfield,SA
从兔视网膜的水平细胞获得细胞内记录，以评估它们对移动和静止的矩形光缝的视觉反应的方向敏感性。随后用辣根过氧化物酶（HRP）标记细胞进行形态学鉴定。发现A型水平细胞和B型水平细胞的体细胞和轴突终末的反应（一个细胞除外）对光刺激的方向不敏感。然而，20个水平细胞内遇到或只是上级的视觉条纹显示出明确的方向敏感的反应特性。这些细胞被分为两组：大多数（70%）表现出偏好平行的视觉条纹取向的光刺激，而其余的首选刺激正交的视觉条纹取向。通过窄的、位移的光缝对这些细胞的感受野的形状的分析揭示了各向异性，其中每个细胞的感受野的长轴或伸长轴沿着与其生理优选取向相同的角度对齐。取向敏感的水平细胞形成了一个均匀的群体，其结构对应于已报道的细长A型或Ae型水平细胞的结构之前在兔子视网膜上的实验这些细胞表现出显着的伸长，其树突状乔木与主轴取向平行或正交的视觉条纹。此外，每个细胞的树突的方向相匹配的生理偏好的方向。因此，目前的结果强烈表明，Ae型水平细胞的方向敏感性直接来自其树突状乔木的不对称性。Ae-型水平细胞的空间位置和专门的生理学表明，它们在兔视网膜中更近端的神经元所表现出的方向敏感特性的形成中发挥作用。
Intracellular recordings were obtained from horizontal cells in the rabbit retina to assess the orientation sensitivity of their visual responses to moving and stationary rectangular slits of light. Cells were subsequently labeled with horseradish peroxidase (HRP) for morphological identification. The responses of A‐type horizontal cells and those of the somatic and axon terminal endings of B‐type horizontal cells (with the exception of one cell) were found to be insensitive to the orientation of light stimuli. However, 20 horizontal cells encountered within or just superior to the visual streak displayed clear orientation‐sensitive response properties. These cells were divided into two groups: the majority (70%) showed preference for light stimuli oriented parallel to the visual streak, whereas the remainder preferred stimuli oriented orthogonal to the visual streak. Analysis of the shape of the receptive fields of these cells by means of a narrow, displaced slit of light revealed an anisotropy with the major or elongated axis of the receptive field of each cell aligned along the same angle as its physiological preferred orientation.Morphologically, the orientation‐sensitive horizontal cells formed a homogeneous group with an architecture corresponding to that of elongated A‐type or Ae‐type horizontal cells reported previously in the rabbit retina. These cells showed a marked elongation of their dendritic arbors with the major axes oriented either parallel or orthogonal to the visual streak. Furthermore, the orientation of the dendritic arbor of each cell matched that of its physiological preferred orientation. The present results, then, suggest strongly that the orientation sensitivity of Ae‐type horizontal cells results directly from the asymmetry in their dendritic arbors. The spatial location and specialized physiology of Ae‐type horizontal cells suggest that they play a role in the formation of orientation‐sensitive properties exhibited by more proximal neurons in the rabbit retina.