Rick D Fetter

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The two margin morphologies of frog retinal cone outer segment (COS) discs were examined by thin sectioning, freeze-fracture, and deep-etch, rotary shadowing techniques. The disc margin adjacent to the connecting cilium, which morphologically resembles the terminal loop of rod outer segment (ROS) discs, exhibited a distinctive staining density tightly(More)
We have applied thin sectioning and freeze-fracture techniques to investigate the terminal loop structure of photoreceptive disks in frog retinal rod outer segments. Our studies of this region demonstrate a highly curved terminal loop bilayer that is continuous with both lamellar bilayers of the disk, and equivalent to them in dimensions and staining(More)
In the process of disk renewal in retinal cone outer segments (COSs), apical displacement of disks must be coupled to systematic reductions in disk area and perimeter in order to retain overall conical geometry. We have quantified these changes in disk area and perimeter segment lengths by morphometric analyses of cross sections of fully formed disks taken(More)
When frog retinas are exposed to light, a series of three-dimensional crystals develop within the outer segment disk system of cones but not rods. The crystals involve components that span cytoplasmic, disk membrane, and intradisk domains of the outer segment. The crystalline membrane domains are directly continuous with adjacent, noncrystalline lamellar(More)
The sense of smell enables animals to react to long-distance cues according to learned and innate valences. Here, we have mapped with electron microscopy the complete wiring diagram of the Drosophila larval antennal lobe, an olfactory neuropil similar to the vertebrate olfactory bulb. We found a canonical circuit with uniglomerular projection neurons (uPNs)(More)
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