title: Localization of zinc in the outer retina of carp: a light- and electron-microscopic study.
abstract: Many lines of evidence suggest that zinc may play an important neuromodulatory role in the central nervous system, including the retina. In this work, localization of zinc in the outer retina of carp was studied, using the silver amplification method, by light and electron microscopy. Reaction products (silver grains) were widely distributed throughout the retina, including photoreceptors, the outer and inner nuclear layers (ONL and INL), the ganglion cell layer (GCL), as well as in both outer and inner plexiform layers (OPL and IPL). Generally, staining for zinc was stronger in the outer retina than in the inner retina, and grains were aggregated with the greatest density in the OPL and the outer limiting membrane (OLM). Silver precipitates were also detected in the inner segments, axons, but not outer segments of photoreceptors. At the ultrastructural level, zinc was localized to myoid regions, mitochondria in the inner segments, internuclear space and nuclei of photoreceptors. In addition, silver grains were found in the terminals of photoreceptors, cone pedicles, and rod spherules, as well as in some processes in the OPL, which might be dendrites of horizontal cells. The presence of zinc in the terminals of photoreceptors suggests that zinc might be released from photoreceptor terminals and play modulatory roles in the outer retina.
authors.affiliation: Institute of Neurobiology, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200032, China.
authors.forename: Shu-Chen
authors.initials: SC
authors.lastname: Lee
authors.forename: Yong-Mei
authors.initials: YM
authors.lastname: Zhong
authors.forename: Rui-Xi
authors.initials: RX
authors.lastname: Li
authors.forename: Zhang
authors.initials: Z
authors.lastname: Yu
authors.forename: Xiong-Li
authors.initials: XL
authors.lastname: Yang
mesh_terms: D000818:Animals; D002347:Carps / Q000378:metabolism*; D008854:Microscopy, Electron; D012160:Retina / Q000033:anatomy & histology / Q000378:metabolism* / Q000648:ultrastructure; D017949:Retinal Cone Photoreceptor Cells / Q000187:drug effects / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000187:drug effects / Q000378:metabolism; D016622:Silver Staining; D013347:Subcellular Fractions / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D015032:Zinc / Q000378:metabolism*
chemical_list: D015032:Zinc