Electroretinographical and histological study of mouse retina after optic nerve section: a comparison between wild-type and retinal degeneration 1 mice

• Published in: Clinical & experimental ophthalmology Vol. 41; no. 6; pp. 593 - 602
• Main Authors: Germain, Francisco, Istillarte, Mirna, Gómez-Vicente, Violeta, Pérez-Rico, Consuelo, de la Villa, Pedro
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01.08.2013; Wiley Subscription Services, Inc
• Subjects: Animals; Axotomy; Cell Count; Cell Death; Cell Survival; Disease Models, Animal; electroretinogram; Electroretinography; Medical research; Mice; Mice, Inbred C57BL; Mice, Inbred ICR; Mice, Mutant Strains; Night Vision - physiology; Optic nerve; Optic Nerve - physiology; Optic Nerve Diseases - diagnosis; Optic Nerve Diseases - physiopathology; optic neuropathy; Retina; Retina - physiopathology; retinal degeneration; Retinal Dystrophies - diagnosis; Retinal Dystrophies - physiopathology; Retinal Ganglion Cells - pathology; Stilbamidines; electroretinogram; optic neuropathy; retinal degeneration; retina
• ISSN: 1442-6404; 1442-9071
• DOI: 10.1111/ceo.12046

Background Retinal ganglion cell death underlies the pathophysiology of neurodegenerative disorders such as glaucoma or optic nerve trauma. To assess the potential influence of photoreceptor degeneration on retinal ganglion cell survival, and to evaluate functionality, we took advantage of the optic nerve section mouse model. Methods Surviving retinal ganglion cells were double‐stained by exposing both superior colliculi to fluorogold, and by applying dextran‐tetramethylrhodamine to the injured optic nerve stump. To assess retinal function in wild‐type animals, electroretinograms were recorded on the injured eyes and compared with the contralateral. Similar labelling experiments were carried out on retinal degeneration 1 mice. Surviving retinal ganglion cells were counted 21 days after axotomy and compared with wild‐type mice. No functional experiments were performed on retinal degeneration 1 animals because they do not develop normal electroretinographical responses. Results A significant decrease in retinal ganglion cell density was observed 6 days after axotomy in the wild type. Functional studies revealed that, in scotopic conditions, axotomy induced a significant amplitude decrease in the positive scotopic threshold response component of the electroretinogram. Such decrease paralleled cell loss, suggesting it may be an appropriate technique to evaluate functionality. When comparing retinal ganglion cell densities in wild‐type and retinal degeneration 1 mice, a significant greater survival was observed on the latter. Conclusions After optic nerve section, electroretinographical recordings exhibited a progressive decrease in the amplitude of the positive scotopic threshold response wave, reflecting ganglion cell loss. Interestingly, rod degeneration seemed, at least initially, to protect from axotomy‐driven damage.