Light-evoked changes in the interphotoreceptor matrix.
The normal function of vertebrate photoreceptor cells depends on multiple interactions and transfer of substances between the photoreceptors and the retinal pigment epithelium (RPE), but the mechanisms of these interactions are poorly understood. Many are thought to be mediated by the interphotoreceptor matrix (IPM), a complex extracellular matrix that surrounds the photoreceptors and lies between them and the RPE. Histochemical, immunocytochemical, and lectin probes for several IPM constituents revealed that components of the IPM in the rat undergo a major shift in distribution or molecular conformation after the transition between light and dark. In the light, various IPM constituents concentrated in bands at the apical and basal regions of the outer segment zone; in the dark, they distributed much more uniformly throughout the zone. The change in IPM distribution was triggered by the light-dark transition; it was not a circadian event, and it was not driven by a systemic factor. The light-evoked change in IPM distribution may facilitate the transfer of substances between the photoreceptors and the RPE.
Department of Anatomy, University of California, San Francisco 94143.
F
F
Uehara
M T
MT
Matthes
D
D
Yasumura
M M
MM
LaVail
D000417:Albinism; D000818:Animals; D003624:Darkness; D005109:Extracellular Matrix / Q000502:physiology; D016650:Fluorescein-5-isothiocyanate / Q000031:analogs & derivatives*; D005452:Fluoresceins; D006001:Glycoconjugates / Q000032:analysis; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D008027:Light; D010786:Photoreceptor Cells / Q000502:physiology* / Q000528:radiation effects; D010857:Pigment Epithelium of Eye / Q000166:cytology / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D012160:Retina / Q000166:cytology / Q000502:physiology* / Q000528:radiation effects; D012374:Rod Cell Outer Segment / Q000502:physiology; D012794:Sialic Acids / Q000032:analysis; D014909:Wheat Germ Agglutinins
D005452:Fluoresceins; D006001:Glycoconjugates; D012794:Sialic Acids; D014909:Wheat Germ Agglutinins; C047939:fluorescein isothiocyanate-wheat germ agglutinin; D016650:Fluorescein-5-isothiocyanate