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C Keri

Publications and source records attributed to C Keri.

3 recordsLinked to original sources

A low cost computer aided design (CAD) system for 3D-reconstruction from serial sections.

This paper describes an approach to computer-assisted 3D-reconstruction of neuronal specimens based on a low cost yet powerful software package for a personal computer (Atari ST). It provides an easy to handle (mouse driven) object editor to create 3D models of medium complexity (15,000 vertices) from sections or from scratch. The models may be displayed in various modes including stereo viewing and complex animation sequences.

Animals↗

Identification of pedicles of putative blue-sensitive cones in the human retina.

Cone photoreceptor pedicles from midperipheral regions of the human retina (6 mm from the foveal center) have been studied by light and electron microscopy. Three areas of cone pedicle mosaic were serially thin-sectioned, in the tangential plane, from the inner border of the outer plexiform layer to the emergence of the cone axons from the cone pedicles. Semithin sections were then collected from the cone axon level through the cone cell bodies to the cone inner segment level. Two hundred twenty-one cone pedicles were followed by this means to their respective inner segments. Eight percent of the cone pedicles were from cones with inner segment characteristics of the blue cones. All 221 cone pedicles were reconstructed by tracing images from electron micrographs. The cone pedicle locations, surface areas, telodendrial projections, and synaptic ribbons could then be measured by morphometry and analyzed by statistical methods. Some selected cone pedicles were reconstructed by computer graphics methods. The cone pedicles identified as belonging to the blue cone type could be distinguished from the surrounding longer wavelength types on the following morphological criteria: 1) they were smaller (50% the area of the surrounding pedicles), 2) they contained shorter synaptic ribbons, 3) they exhibited essentially no telodendrial contact to neighboring cone pedicles, 4) they were positioned slightly more vitread in the outer plexiform layer than neighboring pedicles, and 5) their irregular occurrence in the cone mosaic coincided with the distribution criteria established in our previous paper (Ahnelt et al: J. Comp. Neurol. 255:18-34, '87) for putative blue sensitive cones in midperipheral human retina.

Color Perception↗