Localization of nNOS in photoreceptor, bipolar and horizontal cells in turtle and rat retinas.
Neuronal nitric oxide synthase (nNOS), an enzyme that synthesizes NO, has been found in the outer retina using light microscopic immunocytochemistry, but its subcellular localization is unknown. We used electron immunocytochemistry to examine nNOS-like immunoreactivity (nNOS-LI) in the outer plexiform layer of turtle and rat retinas. In turtle, nNOS-LI was present in some bipolar and horizontal cell processes at photoreceptor ribbon synapses and at basal junctions between photoreceptors. In rat, nNOS-LI was present in some rod bipolar and B-type horizontal cell axon terminals at rod ribbon synapses. These results indicate that in vertebrates, NO is produced by all of the major nerve cell types in the outer retina at specific synaptic contacts.
Haverkamp
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Boston University, Department of Biology, MA 02215, USA.
Eldred
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D000818:Animals; D016764:Cell Polarity / Q000502:physiology; D007150:Immunohistochemistry; D008854:Microscopy, Electron; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I; D010786:Photoreceptor Cells / Q000201:enzymology* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D051381:Rats; D012160:Retina / Q000166:cytology / Q000201:enzymology* / Q000648:ultrastructure; D013569:Synapses / Q000201:enzymology / Q000648:ultrastructure; D014426:Turtles
D009419:Nerve Tissue Proteins; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat