title: Immunohistochemical identification and synaptic inputs to the diffuse bipolar cell type DB1 in macaque retina.
abstract: Detailed analysis of the synaptic inputs to the primate DB1 bipolar cell has been precluded by the absence of a suitable immunohistochemical marker. Here we demonstrate that antibodies for the EF-hand calcium-binding protein, secretagogin, strongly label the DB1 bipolar cell as well as a mixed population of GABAergic amacrine cells in the macaque retina. Using secretagogin as a marker, we show that the DB1 bipolar makes synaptic contact with both L/M as well as S-cone photoreceptors and only minimal contact with rod photoreceptors. Electron microscopy showed that the DB1 bipolar makes flat contacts at both triad-associated and nontriad-associated positions on the cone pedicle. Double labeling with various glutamate receptor subunit antibodies failed to conclusively determine the subunit composition of the glutamate receptors on DB1 bipolar cells. In the IPL, DB1 bipolar cell axon terminals expressed the glycine receptor, GlyRα1, at sites of contact with AII amacrine cells, suggesting that these cells receive input from the rod pathway.
authors: Casey Eye Institute, Department of Ophthalmology, Oregon Health and Sciences University, Portland, Oregon 97239, USA. puthusse@ohsu.edu
authors: Theresa
authors: T
authors: Puthussery
authors: Jacqueline
authors: J
authors: Gayet-Primo
authors: W Rowland
authors: WR
authors: Taylor
authors: Silke
authors: S
authors: Haverkamp
mesh_terms: D025042:Amacrine Cells / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods; D008252:Macaca fascicularis; D016253:Microscopy, Immunoelectron / Q000379:methods; D009434:Neural Pathways / Q000378:metabolism* / Q000648:ultrastructure; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism / Q000648:ultrastructure; D017729:Presynaptic Terminals / Q000378:metabolism / Q000648:ultrastructure; D017470:Receptors, Glutamate / Q000378:metabolism; D012160:Retina / Q000166:cytology / Q000648:ultrastructure; D051245:Retinal Bipolar Cells / Q000502:physiology* / Q000648:ultrastructure; D064046:Secretagogins; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D015415:Biomarkers; D002135:Calcium-Binding Proteins; D017470:Receptors, Glutamate; C576556:SCGN protein, human; D064046:Secretagogins