Goalpha labels ON bipolar cells in the tiger salamander retina.
By using double-label immunocytochemistry and confocal microscopy, we studied rod and cone synaptic contacts, photoreceptor-bipolar cell convergence, and patterns of axon terminal ramification of ON bipolar cells in the tiger salamander retina. An antibody to recoverin, a calcium-binding protein found in photoreceptors and other retinal neurons in various vertebrates, differentially labeled rods and cones by lightly staining rod cell bodies, axons, and synaptic pedicles and heavily staining cone cell bodies and pedicles. An antibody to G(oalpha) labeled most ON bipolar cells, with axon terminals ramified mainly in strata 6-9 and a minor band in stratum 3 of the inner plexiform layer (IPL). Stratum 10 of the IPL was G(oalpha) negative, and previous studies showed that axon terminals of rod-dominated ON bipolar cells are monostratified in that stratum. The axonal morphology of G(oalpha)-positive cells resembled that of the cone-dominated (DBC(C)) or mixed rod and cone ON (DBC(M)) bipolar cells. The G(oalpha)-positive dendritic processes made close contact with all cone pedicles and superficial contact with some rod pedicles, consistent with the idea that G(oalpha) subunits are present in DBC(C)s and DBC(M)s. The size and density of these cells were analyzed, and their spatial distributions were determined. To our knowledge, this is the first study to characterize photoreceptor inputs and axon terminal morphology of a population of ON bipolar cell with the use of a G(oalpha) antibody as an immunomarker in the salamander retina.
Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030, USA. jianz@bcm.tmc.edu
Jian
J
Zhang
Samuel M
SM
Wu
D000557:Ambystoma / Q000033:anatomy & histology / Q000378:metabolism*; D000818:Animals; D000906:Antibodies; D002135:Calcium-Binding Proteins / Q000378:metabolism; D048429:Cell Size / Q000502:physiology; D003712:Dendrites / Q000378:metabolism / Q000648:ultrastructure; D005136:Eye Proteins; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism*; D051597:Hippocalcin; D007395:Interneurons / Q000166:cytology / Q000378:metabolism*; D008074:Lipoproteins; D018613:Microscopy, Confocal; D009419:Nerve Tissue Proteins; D009434:Neural Pathways / Q000378:metabolism* / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism* / Q000648:ultrastructure; D051603:Recoverin; D012160:Retina / Q000166:cytology / Q000378:metabolism*; D017949:Retinal Cone Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000166:cytology / Q000378:metabolism; D009435:Synaptic Transmission / Q000502:physiology; D014785:Vision, Ocular / Q000502:physiology
D000906:Antibodies; D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; D051603:Recoverin; D051597:Hippocalcin; D019206:GTP-Binding Protein alpha Subunits, Gi-Go; D020962:Heterotrimeric GTP-Binding Proteins