title: Forced exercise protects the aged optic nerve against intraocular pressure injury.
abstract: We have previously shown that the optic nerve of mice becomes increasingly vulnerable to injury with advancing age. Here, we investigated whether regular exercise can modify this age-related vulnerability and improve optic nerve recovery after injury. Aged (12-month-old) C57BL/6J mice were exercised by swimming for 60 min/d, 5 d/wk for 6 weeks. After 5 weeks, injury to the optic nerve was induced by short-term elevation of intraocular pressure. Retinal function was recorded using the electroretinogram and the cellular and biochemical changes induced by injury were assessed using immunohistochemistry and quantitative polymerase chain reaction. We found that exercise almost completely reversed age-related vulnerability of the optic nerve to injury such that exercised aged mice had a similar functional response to injury as non-exercised young (3-month-old) mice. Exercise also abrogated injury-induced astrocytic gliosis and macrophage activation in the aged retina. These data suggest that the known benefits of exercise also extend to the visual system and support further investigation of physical activity as a means of protecting against injury, dysfunction, and degeneration in the aging eye.
authors: Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia. Electronic address: vickic@unimelb.edu.au.
authors: Vicki
authors: V
authors: Chrysostomou
authors: Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia; Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
authors: Jelena M
authors: JM
authors: Kezic
authors: Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.
authors: Ian A
authors: IA
authors: Trounce
authors: Centre for Eye Research Australia, University of Melbourne, Royal Victorian Eye and Ear Hospital, East Melbourne, Victoria, Australia.
authors: Jonathan G
authors: JG
authors: Crowston
mesh_terms: D000375:Aging / Q000473:pathology; D000818:Animals; D005911:Gliosis / Q000517:prevention & control; D007429:Intraocular Pressure; D008262:Macrophage Activation; D008810:Mice, Inbred C57BL; D020221:Optic Nerve Injuries / Q000209:etiology / Q000517:prevention & control*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D012160:Retina / Q000166:cytology / Q000473:pathology; D012162:Retinal Degeneration / Q000517:prevention & control
keywords: Exercise; Neuroprotection; Optic nerve; Retina