title: A comparative radioautographic study of the bidirectional axonal and transcellular transport of different amino acids and sugars in the lamprey visual system.
abstract: Following recent radioautographic evidence for the bidirectional axonal transport of [3H]proline from the eye of Lampetra fluviatilis, the present study examined the anterograde and/or retrograde labeling properties of 11 other amino acids and two sugars after intraocular injections of these tritiated substances in the lamprey. The intraocular injections of aspartic acid, glutamic acid, gamma-aminobutyric acid, arginine, phenylalanine, fucose and acetyl glucosamine resulted in a weak labeling of the primary visual centers: there was no evidence of either the transcellular transport of these tracers or the retrograde labeling of the retinopetal neurons. The primary visual system was found to be heavily labeled 24 h after eye injections of alanine, leucine, glycine, lysine, serine and valine. Among the latter only glycine produced a retrograde somatic labeling of retinopetal neurons. With a longer survival period (7 days), a specific transneuronal labeling was also noted after glycine injections. The significance of the differential uptake and transport of these different tracers in the lamprey visual system and possible mechanisms involved in the axonal retrograde transport of [3H]glycine and [3H]proline in the centrifugal pathways are discussed.
mesh_terms: D000117:Acetylglucosamine / Q000378:metabolism*; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001345:Autoradiography; D001369:Axons / Q000378:metabolism*; D001693:Biological Transport, Active; D001921:Brain / Q000378:metabolism; D005123:Eye / Q000166:cytology; D005643:Fucose / Q000378:metabolism*; D005944:Glucosamine / Q000031:analogs & derivatives*; D007267:Injections; D007798:Lampreys; D014795:Visual Pathways / Q000166:cytology / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D005643:Fucose; D005944:Glucosamine; D000117:Acetylglucosamine