The visual system of the Florida garfish, Lepisosteus platyrhincus (Ginglymodi). I. Retina.
The visual system of the Florida garfish, Lepisosteus platyrhincus (Ginglymodi). I. Retina.
复制标题
佛罗里达长嘴鱼 Lepisosteus platyrhincus (Ginglymodi) 的视觉系统。
DOI：
10.1159/000114142
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Collin,HB
中科院分区：
文献类型：
--
作者：
Collin,SP;Collin,HB
在光镜和电镜下观察了佛罗里达长吻鲨Lepisosteus platyrhincus（Ginglymodi）的视网膜和脉络膜毛细血管。内界膜由玻璃体动脉发出的广泛的玻璃体血管系统覆盖，玻璃体动脉在细长的视神经乳头的近端从腹侧进入眼睛。两种大小的神经节细胞索马体被视神经轴突束和Müller细胞终足分隔，所有这些都位于神经节细胞层的水平。第三类“移位的”神经节细胞位于紧密堆积的无长突、双极和Müller细胞索马之间的内丛状层和内核层的边界。两层水平细胞位于突触区的玻璃体上，突触区由水平和双极树突组成，它们分别内陷杆小球和锥蒂，形成单个和多个（3 - 6个）突触带连接。立即玻璃体的感光细胞核谎言的人口'位移'双极。三种类型的光感受器的特点：不等双锥，单锥（大和小）和杆。这些显示视网膜运动，其中杆在光下伸长，并被色素上皮掩盖，在黑暗中收缩，因为色素迁移到巩膜。超微结构，4种类型的深染（嗜酸性）颗粒描述：（1）小糖原颗粒（0.033 µm）聚集在感光细胞核和更大的类似颗粒的基部（0.078 µm，称为抛物面）玻璃体至椭圆体;（2）绒毡层颗粒（0.32 µm）分布于视网膜色素上皮（RPE）的背侧五分之四;（3）色素颗粒（4）脉络膜毛细血管的颗粒或黑素体（0.813 µm）。第二类颗粒构成一个绒毡层，在黑暗中观察时，会发出黄色的光泽。另外两种绒毡层也存在，鸟嘌呤绒毡层（不规则的鸟嘌呤晶体）和纤维绒毡层（胶原纤维的堆叠）。功能的相关性，并假定祖先（原始）的条件下，特定的视觉字符建立的射线鳍鱼类组外比较。
The retina and choriocapillaris of the Florida garfish,Lepisosteus platyrhincus(Ginglymodi), was examined at the light and electron microscopic levels. The inner limiting membrane is covered by an extensive system of vitreal blood vessels emanating from the hyaloid artery, which enters the eye ventrally at the proximal end of the elongated optic nerve head. Two size classes of ganglion cell soma are segregated by optic axon fascicles and MÜller cell endfeet, all of which lie at the level of the ganglion cell layer. A third class of 'displaced' ganglion cells lies at the border of the inner plexiform and inner nuclear layers amidst tightly packed amacrine, bipolar and MÜller cell soma. Two layers of horizontal cells lie vitread of a synaptic zone consisting of a complex arrangement of horizontal and bipolar dendrites invaginating rod spherules and cone pedicles to form single and multiple (three to six) synaptic ribbon connections, respectively. Immediately vitread of the photoreceptor nuclei lie a population of 'displaced' bipolars. Three types of photoreceptors are characterised: unequal double cones, single cones (large and small) and rods. These show retinomotor movements where the rods elongate in the light and are masked by the pigment epithelium and contract in the dark as the pigment migrates sclerad. Ultrastructurally, 4 types of dark-staining (osmophilic) granules are described: (1) Small glycogen granules (0.033 µm) aggregated at the bases of the photoreceptor nuclei and larger similar granules (0.078 µm and termed paraboloids) vitread to the ellipsoid; (2) tapetal granules (0.32 µm) distributed throughout the dorsal four-fifths of the retinal pigment epithelium (RPE); (3) pigment granules (0.5–2.0 µm) in the RPE, concentrated in ventral retina; (4) granules or melanosomes (0.813 µm) of the choriocapillaris. The second class of granules constitute a tapetum lucidum eliciting a yellow eyeshine when viewed in the dark. Two other tapeta also exist, a guanine tapetum (irregular guanine crystals) and a tapetum fibrosum (stacks of collagen fibrils). Functional correlations are made, and the putative ancestral (primitive) condition of particular visual characters is established for the ray-finned fishes by out-group comparisons.