title: PKC{alpha} is essential for the proper activation and termination of rod bipolar cell response.
abstract: OBJECTIVE
  Protein kinase (PKC)-α is abundant in retinal bipolar cells. This study was performed to explore its role in visual processing.
  
  
  METHODS
  PKCα-knockout (Prkca(-/-)) mice and control animals were examined by using electroretinography (ERG), light microscopy, and immunocytochemistry.
  
  
  RESULTS
  The Prkca(-/-) mice showed no signs of retinal degeneration up to 12 months of age, but ERG measurements indicated a decelerated increase in the ascending limb of the scotopic (rod-sensitive) b-wave as well as a delayed return to baseline. These results suggest that PKCα is an important modulator that affects bipolar cell signal transduction and termination. Confocal microscopy of retinal sections showed that PKCα co-localized with calbindin, which indicates a PKCα localization in close proximity to the horizontal cell terminals. In addition, the implicit time of the ERG c-wave originating from the retinal pigment epithelium (RPE) and the recovery of photoreceptors from bleaching conditions were substantially faster in the knockout mice than in the wild-type control animals.
  
  
  CONCLUSIONS
  These results suggest that PKCα is a modulator of rod-bipolar cell function by accelerating glutamate-driven signal transduction and termination. This modulation is of importance in the switch between scotopic and photopic vision. Furthermore, PKCα seems to play a role in RPE function.
authors.affiliation: Charité- Eye-Hospital, Campus Virchow-Klinikum, Universitätsmedizin Berlin, Berlin, Germany. ruether@freenet.de
authors.forename: Klaus
authors.initials: K
authors.lastname: Ruether
authors.forename: Andreas
authors.initials: A
authors.lastname: Feigenspan
authors.forename: Judith
authors.initials: J
authors.lastname: Pirngruber
authors.forename: Michael
authors.initials: M
authors.lastname: Leitges
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Baehr
authors.forename: Olaf
authors.initials: O
authors.lastname: Strauss
mesh_terms: D000818:Animals; D015139:Blotting, Southern; D003623:Dark Adaptation; D004596:Electroretinography; D005260:Female; D005838:Genotype; D007150:Immunohistochemistry; D008027:Light; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008853:Microscopy; D016133:Polymerase Chain Reaction; D051571:Protein Kinase C-alpha / Q000502:physiology*; D051245:Retinal Bipolar Cells / Q000201:enzymology* / Q000528:radiation effects; D017948:Retinal Rod Photoreceptor Cells / Q000201:enzymology* / Q000528:radiation effects; D014785:Vision, Ocular / Q000502:physiology*
chemical_list: D051571:Protein Kinase C-alpha