期刊名称:Proceedings of the National Academy of Sciences
印刷版ISSN:0027-8424
电子版ISSN:1091-6490
出版年度:1973
卷号:70
期号:6
页码:1677-1681
DOI:10.1073/pnas.70.6.1677
语种:English
出版社:The National Academy of Sciences of the United States of America
摘要:In the outer plexiform layer of the retina the synaptic endings of cone cells make specialized junctions with each other and with the endings of rod cells. The ultrastructure of these interreceptor junctions is described in retinas of monkeys, rabbits, and turtles, in thin sections of embedded specimens and by the freeze-fracturing technique. Cone-to-rod junctions are ribbon-like areas of close membrane approximation. On either side of the narrowing of the intercellular space, the junctional membranes contain a row of particles located on the fracture face A (cytoplasmic leaflet), while the complementary element, a row of single depressions, is located on fracture face B. The particle rows are surrounded by a membrane region that is devoid of particulate inclusions and bears an adherent layer of dense cytoplasmic material. Cone-to-cone junctions in some places are identical to cone-to-rod junctions, while in other places they closely resemble typical gap junctions (nexus). Interreceptor junctions, therefore, represent a morphological variant of the gap junction, and probably mediate electrotonic coupling between neighboring photoreceptor cells.
关键词:membranes ; electron microscopy ; freeze-fracturing