title: Cholecystokinin-like immunoreactive amacrine cells in the rat retina.
abstract: High levels of endogenous cholecystokinin (CCK) are present in the rat retina (Eskay & Beinfeld, 1982), but the cellular localization and physiological actions of CCK in the rat retina are uncertain. The goals of this study were to characterize the cells containing CCK, identify cell types that interact with CCK cells, and investigate the effects of CCK on rod bipolar cells. Rat retinas were labeled with antibody to gastrin-CCK (gCCK) using standard immunofluorescence techniques. Patch-clamp methods were used to record from dissociated rod bipolar cells from rats and mice. Gastrin-CCK immunoreactive (-IR) axons were evenly distributed throughout the retina in stratum 5 of the inner plexiform layer of the rat retina. However, the gCCK-IR somata were only detected in the ganglion cell layer in the peripheral retina. The gCCK-IR cells contained glutamate decarboxylase, and some of them also contained immunoreactive substance P. Labeled axons contacted PKC-IR rod bipolar cells, and recoverin-IR ON-cone bipolar cells. CCK-octapeptide inhibits GABA(C) but not GABA(A) mediated currents in dissociated rod bipolar cells.
authors.affiliation: Department of Neurobiology and Anatomy, University of Texas Houston Medical School, Houston 77030, USA.
authors.forename: Sally I
authors.initials: SI
authors.lastname: Firth
authors.forename: Carolina
authors.initials: C
authors.lastname: Varela
authors.forename: Pedro
authors.initials: P
authors.lastname: De la Villa
authors.forename: David W
authors.initials: DW
authors.lastname: Marshak
mesh_terms: D025042:Amacrine Cells / Q000378:metabolism*; D000818:Animals; D001369:Axons / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000378:metabolism; D002766:Cholecystokinin / Q000378:metabolism*; D004553:Electric Conductivity; D005136:Eye Proteins; D005455:Fluorescent Antibody Technique; D005755:Gastrins / Q000378:metabolism; D005968:Glutamate Decarboxylase / Q000378:metabolism; D051597:Hippocalcin; D066298:In Vitro Techniques; D008074:Lipoproteins; D051379:Mice; D009419:Nerve Tissue Proteins; D018408:Patch-Clamp Techniques; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D020318:Rats, Long-Evans; D017207:Rats, Sprague-Dawley; D018079:Receptors, GABA / Q000502:physiology; D051603:Recoverin; D012160:Retina / Q000166:cytology / Q000378:metabolism; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism; D012165:Retinal Ganglion Cells / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000502:physiology; D012844:Sincalide / Q000494:pharmacology; D013373:Substance P / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D002135:Calcium-Binding Proteins; D005136:Eye Proteins; D005755:Gastrins; D008074:Lipoproteins; D009419:Nerve Tissue Proteins; C496732:Rcvrn protein, mouse; C496733:Rcvrn protein, rat; D018079:Receptors, GABA; D051603:Recoverin; D051597:Hippocalcin; D013373:Substance P; D002766:Cholecystokinin; D011493:Protein Kinase C; D005968:Glutamate Decarboxylase; D012844:Sincalide