title: The Effect of PKCα on the Light Response of Rod Bipolar Cells in the Mouse Retina.
abstract: OBJECTIVE
  Protein kinase C α (PKCα) is abundantly expressed in rod bipolar cells (RBCs) in the retina, yet the physiological function of PKCα in these cells is not well understood. To elucidate the role of PKCα in visual processing in the eye, we examined the effect of genetic deletion of PKCα on the ERG and on RBC light responses in the mouse.
  
  
  METHODS
  Immunofluorescent labeling was performed on wild-type (WT), TRPM1 knockout, and PKCα knockout (PKC-KO) retina. Scotopic and photopic ERGs were recorded from WT and PKC-KO mice. Light responses of RBCs were measured using whole-cell recordings in retinal slices from WT and PKC-KO mice.
  
  
  RESULTS
  Protein kinase C alpha expression in RBCs is correlated with the activity state of the cell. Rod bipolar cells dendrites are a major site of PKCα phosphorylation. Electroretinogram recordings indicated that loss of PKCα affects the scotopic b-wave, including a larger peak amplitude, longer implicit time, and broader width of the b-wave. There were no differences in the ERG a- or c-wave between PKCα KO and WT mice, indicating no measurable effect of PKCα in photoreceptors or the RPE. The photopic ERG was unaffected consistent with the lack of detectable PKCα in cone bipolar cells. Whole-cell recordings from RBCs in PKC-KO retinal slices revealed that, compared with WT, RBC light responses in the PKC-KO retina are delayed and of longer duration.
  
  
  CONCLUSIONS
  Protein kinase C alpha plays an important modulatory role in RBCs, regulating both the peak amplitude and temporal properties of the RBC light response in the rod visual pathway.
authors.affiliation: Department of Physiology & Pharmacology Oregon Health & Science University, Portland, Oregon, United States.
authors.forename: Wei-Hong
authors.initials: WH
authors.lastname: Xiong
authors.affiliation: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Ji-Jie
authors.initials: JJ
authors.lastname: Pang
authors.affiliation: Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, United States.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Pennesi
authors.affiliation: Department of Physiology & Pharmacology Oregon Health & Science University, Portland, Oregon, United States.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Duvoisin
authors.affiliation: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas, United States.
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Wu
authors.affiliation: Department of Physiology & Pharmacology Oregon Health & Science University, Portland, Oregon, United States.
authors.forename: Catherine W
authors.initials: CW
authors.lastname: Morgans
mesh_terms: D000818:Animals; D015153:Blotting, Western; D004247:DNA / Q000235:genetics*; D004195:Disease Models, Animal; D004596:Electroretinography; D005786:Gene Expression Regulation; D015316:Genetic Therapy / Q000379:methods; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D018408:Patch-Clamp Techniques; D051571:Protein Kinase C-alpha / Q000096:biosynthesis / Q000235:genetics*; D051245:Retinal Bipolar Cells / Q000201:enzymology* / Q000473:pathology; D012164:Retinal Diseases / Q000201:enzymology / Q000235:genetics* / Q000503:physiopathology; D017948:Retinal Rod Photoreceptor Cells / Q000201:enzymology* / Q000473:pathology; D014795:Visual Pathways / Q000201:enzymology* / Q000503:physiopathology
chemical_list: D004247:DNA; D051571:Protein Kinase C-alpha