Zusammenfassung
PURPOSE. Protein kinase (PKC)-alpha is abundant in retinal bipolar cells. This study was performed to explore its role in visual processing. METHODS. PKC alpha-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 ...
Zusammenfassung
PURPOSE. Protein kinase (PKC)-alpha is abundant in retinal bipolar cells. This study was performed to explore its role in visual processing. METHODS. PKC alpha-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 PKC alpha is an important modulator that affects bipolar cell signal transduction and termination. Confocal microscopy of retinal sections showed that PKC alpha co-localized with calbindin, which indicates a PKC alpha 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 PKC alpha 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, PKC alpha seems to play a role in RPE function. (Invest Ophthalmol Vis Sci.2010;51:6051-6058) DOI:10.1167/iovs.09-4704