title: Myelin pathogenesis and functional deficits following SCI are age-associated.
abstract: Most spinal cord injuries (SCI) occur in young adults. In the past few decades however, the average age at time of SCI and the percentage of injuries in persons over the age of 60 have increased. Studies have shown that there is an age-associated delay in the rate of remyelination following toxin-induced demyelination of the spinal cord, suggesting that there may be an age-associated difference in regenerative efficiency. Here we examine for the first time locomotor recovery, bladder recovery, and myelin pathology in young (3 months), aged (12 months), and geriatric (24 months) female rats following contusion SCI. Our assessments indicate that aged and geriatric rats have a delayed rate of locomotor recovery following contusion SCI as compared to young rats. Additionally, aged and geriatric rats have significantly slower bladder recovery as compared to young rats. Examination of myelin pathology reveals that aged and geriatric rats have significantly greater area of pathology and amount of demyelination, as well as significantly less remyelination as compared to young rats following contusion SCI. These data are the first to indicate that there is an age-associated decline in the rate and extent of both locomotor and bladder recovery following contusion SCI, and that age adversely affects the degree of general pathology, demyelination, and remyelination that accompanies contusion SCI.
authors.affiliation: Reeve-Irvine Research Center, Sue and Bill Gross Stem Cell Research Center, Department of Anatomy and Neurobiology, School of Medicine, University of California at Irvine, Irvine, CA 92697-4292, USA.
authors.forename: Monica M
authors.initials: MM
authors.lastname: Siegenthaler
authors.forename: Denise L
authors.initials: DL
authors.lastname: Ammon
authors.forename: Hans S
authors.initials: HS
authors.lastname: Keirstead
mesh_terms: D000367:Age Factors; D000375:Aging / Q000473:pathology* / Q000502:physiology; D000818:Animals; D003711:Demyelinating Diseases / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D009043:Motor Activity / Q000502:physiology; D009186:Myelin Sheath / Q000473:pathology; D009413:Nerve Fibers, Myelinated / Q000473:pathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology; D013119:Spinal Cord Injuries / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D001745:Urinary Bladder Diseases / Q000209:etiology / Q000473:pathology / Q000503:physiopathology