Hayes B P, Webster K E
Neuroscience. 1985 Nov;16(3):641-57. doi: 10.1016/0306-4522(85)90198-8.
The cytoarchitecture in the retinoreceptive zone of the pigeon optic tectum has been studied in Nissl-stained sections taken in four planes. As suggested by a previous study, two cytoarchitectural fields are present. Reconstructed views of the tectum show that the fields are separated by a narrow transition zone approximating to the tectal representation of the retina's horizontal meridian. In field 1 (which is upper and rostral), sublayer IIb is wide, IIc wide and trilaminate, IId narrow and IIe continuous; in field 2, IIb and c are narrow, IId wide and IIe discontinuous. The distribution of retinal terminals was investigated by the anterograde axonal transport of [3H]proline or horseradish peroxidase from intravitreal injections. The depth distribution of grains or reaction product throughout the entire tectum was quantified by scanning with a microdensitometer. Both autoradiography and horseradish peroxidase transport show two patterns of lamination separated by a narrow transition zone and these two terminal fields correspond closely to the cytoarchitectural fields. In field 1 optic terminals are concentrated in sublayer IIb, superficial c, d, and to a lesser extent in f; in field 2 concentrations are present at the IIb/c boundary, across deep IIc and d, and a small concentration is found IIf. The patterns of retinal termination with depth in the tectum found by axonal transport are compatible with those found by electron microscopy, and are discussed in relation to the optic termination found by other techniques. Study of the time course of axonal transport shows that both radioactive material and horseradish peroxidase are fast transported to all the bands of optic terminals at about 150 mm/day. Horseradish peroxidase gradually accumulates in the retinoreceptive zone, filling clusters of terminals and horizontal processes. At 12 days, it has begun to disappear from the zone and a few diffusely filled profiles, that may be transcellularly labelled, are present. Electron microscope autoradiography of fast transported material shows clusters of grains over optic terminals and preterminals and a percentage density analysis confirms that these profiles are specifically labelled. The two tectal fields each contain the projection from specialized areas of the retina, suggesting functional specialization in the tectum for the processing of different kinds of visual information.
通过对取自四个平面的尼氏染色切片进行研究，分析了鸽视顶盖视网膜感受区的细胞结构。正如之前一项研究所表明的，存在两个细胞结构区域。顶盖的重建视图显示，这两个区域由一个狭窄的过渡带分隔，该过渡带大致相当于视网膜水平子午线在顶盖的表征。在区域1（位于上方且靠前），IIb亚层较宽，IIc宽且呈三层结构，IId窄，IIe连续；在区域2，IIb和IIc窄，IId宽，IIe不连续。通过玻璃体内注射[3H]脯氨酸或辣根过氧化物酶的顺行轴突运输来研究视网膜终末的分布。用微密度计扫描对整个顶盖中颗粒或反应产物的深度分布进行定量。放射自显影和辣根过氧化物酶运输均显示出由一个狭窄过渡带分隔的两种分层模式，这两个终末区域与细胞结构区域密切对应。在区域1，视终末集中在IIb亚层、浅层的IIc、IId，在IIf层的程度较小；在区域2，集中在IIb/c边界、深层的IIc和IId，在IIf层有少量集中。通过轴突运输在顶盖中发现的视网膜终末随深度的模式与通过电子显微镜发现的模式相符，并结合其他技术发现的视终末情况进行了讨论。对轴突运输时间进程的研究表明，放射性物质和辣根过氧化物酶均以约150毫米/天的速度快速运输到所有视终末带。辣根过氧化物酶逐渐在视网膜感受区积累，填充终末簇和水平突起。在12天时，它已开始从该区域消失，并且存在一些可能是经细胞标记的弥漫性填充轮廓。快速运输物质的电子显微镜放射自显影显示视终末和终末前有颗粒簇，百分比密度分析证实这些轮廓被特异性标记。两个顶盖区域各自包含来自视网膜特定区域的投射，这表明顶盖在处理不同类型视觉信息方面具有功能特化。
