Expression of connexin 35/36 in retinal horizontal and bipolar cells of carp

• Published in: Neuroscience 2009-12, Vol.164 (3), p.1161-1169
• Main Authors: Liu, C.R, Xu, L, Zhong, Y.M, Li, R.X, Yang, X.L
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; bipolar cells; Carps - anatomy & histology; Carps - metabolism; connexin 35/36; Connexins - metabolism; Dendrites - metabolism; Dendrites - ultrastructure; Eye and associated structures. Visual pathways and centers. Vision; Fluorescent Antibody Technique; Freshwater; Fundamental and applied biological sciences. Psychology; Gap Junctions - metabolism; Gap Junctions - ultrastructure; horizontal cells; immunofluroscence double labeling; Microscopy, Confocal; Microscopy, Electron, Transmission; Neural Pathways - cytology; Neural Pathways - metabolism; Neurology; retina; Retina - cytology; Retina - metabolism; Retinal Bipolar Cells - cytology; Retinal Bipolar Cells - metabolism; Retinal Cone Photoreceptor Cells - metabolism; Retinal Cone Photoreceptor Cells - ultrastructure; Retinal Horizontal Cells - cytology; Retinal Horizontal Cells - metabolism; Retinal Rod Photoreceptor Cells - metabolism; Retinal Rod Photoreceptor Cells - ultrastructure; Signal Transduction - drug effects; Signal Transduction - physiology; Synapses - metabolism; Synapses - ultrastructure; Synaptic Membranes - metabolism; Synaptic Membranes - ultrastructure; Synaptic Transmission - drug effects; Synaptic Transmission - physiology; Vertebrates: nervous system and sense organs; Vision, Ocular - physiology; Visual Pathways - cytology; Visual Pathways - metabolism
• ISSN: 0306-4522; 1873-7544
• DOI: 10.1016/j.neuroscience.2009.09.035

Abstract Connexin 35/36 (Cx35/36) gap junction protein is expressed in various regions of the brain, including the retina. In this work, the expression of Cx35/36 in the outer retina of carp was studied by immunocytochemistry. By light microscopy, strong punctate Cx35/36-immunoreactivity was observed in the outer plexiform layer. Double labeling experiments on vertical retinal sections showed that Cx35/36 puncta were localized beneath cone pedicles, stained by recoverin, but not on them. In addition, few of the dendrites of rod-dominant ON type bipolar cells (rod-ON-BCs), stained by PKCα, were labelled with Cx35/36 in the retinal sections. In isolated cell preparations, Cx35/36 was clearly expressed on the dendrites of cone-dominant ON type bipolar cells (cone-ON-BCs), but the expression was much less on rod-ON-BCs. Moreover, Cx35/36 puncta were found in the dendrites of isolated horizontal cells (labelled by GAD 65/67) driven by cones, including H1 and H2 cells, but not in those of cells driven by rods (H4 cells). At the ultrastructural level, reaction product was found in H1 and H2 cell dendrites invaginating cone terminals, but not in H4 cell dendrites invaginating rod terminals. Moreover, dendrites of cone-ON-BCs, were also labebed. These results suggest that Cx35/36 could be specifically involved in modulation of the cone signal pathway in the outer retina of carp.