|
|
||||||||
1From the Departments of Cell Biology and Anatomy, and 2Surgery/Division of Ophthalmology, 3Neuroscience Research Group and 4Lions Sight Centre, University of Calgary Faculty of Medicine, Calgary, Alberta, Canada; 5Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Peoples Republic of China; 6College of Optometry, University of Houston, Houston, Texas.
PURPOSE. To demonstrate regulation of ocular growth and refractive development by image quality and processing in the retina in higher primates. Focus-sensitive retinal neurons were labeled with immunocytochemical markers after briefly altering image quality in infant monkeys.
METHODS. Six rhesus monkeys (Macaca mulatta) 20- to 30-days-old were fitted with goggles after 6 hours in the light. Three wore a +3 D lens and three a diffuser on the treated eye; contralateral control eyes wore plano lenses matched in transmission to the goggles on treated eyes. After 30, 60, or 240 minutes exposure, the animals were killed, the eyes opened and fixed in 4% formaldehyde, and cryosections labeled with antibodies to inducible activity markers (transcription factors Egr-1 and Fra-2) and type-specific amacrine cell markers. Labeled cells were identified and counted in a fluorescence microscope, and the spatial density of activity-labeled nuclei and the frequency of activity-labeling of specific amacrine cells were determined, without knowing treated eye or duration.
RESULTS. Focus-sensitive immunoreactivity was demonstrated for Egr-1 and Fra-2 in a GAD65-immunoreactive (IR) subpopulation of GABAergic amacrine cells, and for Egr-1 alone in PKCalpha-, 115A10-, and CD15-IR ON-bipolar cells. Activity of ON-bipolar and GABAergic amacrine cells, as indicated by Egr-1 induction, was stimulated more by in-focus or myopically-defocused images than by hyperopically-defocused or diffusely blurred images, regardless of exposure duration.
CONCLUSIONS. This was the first evidence of focus-dependent activation of bipolar as well as amacrine cells in a primate retina. Focus-sensitive neurons are candidates for roles in vision-dependent regulation of eye growth.
This article has been cited by other articles:
![]() |
R. Schippert, E. Burkhardt, M. Feldkaemper, and F. Schaeffel Relative Axial Myopia in Egr-1 (ZENK) Knockout Mice Invest. Ophthalmol. Vis. Sci., January 1, 2007; 48(1): 11 - 17. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Han, M. K. H. Yap, J. Wang, and S. P. Yip Family-Based Association Analysis of Hepatocyte Growth Factor (HGF) Gene Polymorphisms in High Myopia. Invest. Ophthalmol. Vis. Sci., June 1, 2006; 47(6): 2291 - 2299. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Vessey, K. A. Lencses, D. A. Rushforth, V. J. Hruby, and W. K. Stell Glucagon Receptor Agonists and Antagonists Affect the Growth of the Chick Eye: A Role for Glucagonergic Regulation of Emmetropization? Invest. Ophthalmol. Vis. Sci., November 1, 2005; 46(11): 3922 - 3931. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. A. Vessey, D. A. Rushforth, and W. K. Stell Glucagon- and Secretin-Related Peptides Differentially Alter Ocular Growth and the Development of Form-Deprivation Myopia in Chicks Invest. Ophthalmol. Vis. Sci., November 1, 2005; 46(11): 3932 - 3942. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |