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Abstract #21487 Published in IGR 10-3
Loss of melanopsin-containing retinal ganglion cells in a rat glaucoma model
Wang HZ; Lu QJ; Wang NL; Liu H; Zhang L; Zhan GLChinese Medical Journal 2008; 121: 1015-1019
BACKGROUND: Glaucoma can cause progressive damage to retinal ganglion cells. These cells can be classified as cells projecting to the superior colliculus and melanopsin-containing retinal ganglion cells, which project to the suprachiasmatic nucleus. This study was to investigate the effects of chronic intraocular pressure elevation on melanopsin-containing retinal ganglion cells in rats. METHODS: Chronic intraocular pressure elevation was induced in one eye of adult Wistar rats by cauterization of three episcleral veins. Intraocular pressure was measured at different intervals with a rebound tonometer. Superior collicular retinal ganglion cells were retrogradely labeled from the superior colliculus with Fluorogold. Melanopsin-containing retinal ganglion cells were visualized by free-floating immunohistochemistry on whole-mount retinas. The number of labeled superior collicular and melanopsin-containing retinal ganglion cells were counted in the sample areas on flat-mounted retinas. RESULTS: Compared with contralateral control eyes, the numbers of both superior collicular and melanopsin-containing retinal ganglion cells were significantly reduced after 12 weeks of experimental intraocular pressure elevation ((2317.41 ± 29.96)/mm2 vs (1815.82 ± 24.25)/mm2; (26.20 ± 2.10)/mm2 vs (20.62 ± 1.52)/mm2, respectively). The extent of cell loss of the two types of retinal ganglion cells was similar. However, no morphologic changes were found in melanopsin-containing retinal ganglion cells. CONCLUSION: Both melanopsin-containing and superior collicular retinal ganglion cells were damaged by chronic ocular hypertension, indicating that glaucomatous neural degeneration involves the non-image-forming visual pathway.
Dr. H.Z. Wang, Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
Classification:
5.1 Rodent (Part of: 5 Experimental glaucoma; animal models)
2.13 Retina and retinal nerve fibre layer (Part of: 2 Anatomical structures in glaucoma)
3.3 Immunohistochemistry (Part of: 3 Laboratory methods)