title: The effects of age on the morphometry of the cervical spinal cord and spinal column in adult rats: an MRI-based study.
abstract: Rat models are commonly used to investigate the pathophysiological pathways and treatment outcomes after spinal cord injury (SCI). The high incidence of fall-induced SCI in older adults has created a need for aging models of SCI in rats to investigate potential age-related differences in SCI severity and outcomes. The aims of this study were to determine the influences of age and vertebral level on the geometries of the cervical spinal cord and spinal column in a rat model. Three young (3 months) and three aged (12 months) Fischer 344 rats were imaged in a high field (7 T) small-animal magnetic resonance imaging system. All spinal cord geometry variables (including depth, width, and axial cross-sectional area) and one spinal canal variable (depth) were significantly larger in the aged specimens by an average of 8.1%. There were main effects of vertebral level on all spinal cord variables and four spinal canal variables with values generally larger at C4 as compared to C6 (average increases ranged from 5.7% to 12.9% in spinal cord measures and 5.4% to 6.8% in spinal canal measures). High inter-rater reliability between two measurers was observed with a mean intraclass correlation of 0.921 and percent difference of 0.9% across all variables measured. This study clearly demonstrates that cervical spinal cord geometry changes between the ages of 3 and 12 months in Fischer 344 rats. This information can aid in the planning and interpretation of studies that use a rat model to investigate the influence of age on cervical SCI.
authors.affiliation: Injury Biomechanics and Aging Laboratory, Department of Kinesiology, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1, Canada; International Collaboration on Repair Discoveries (ICORD), University of British Columbia, 818 West 10th Avenue, Vancouver, British Columbia, V5Z 1M9, Canada.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Laing
authors.forename: Elora C
authors.initials: EC
authors.lastname: Brenneman
authors.forename: Andrew
authors.initials: A
authors.lastname: Yung
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Piotr
authors.initials: P
authors.lastname: Kozlowski
authors.forename: Thomas
authors.initials: T
authors.lastname: Oxland
mesh_terms: D000367:Age Factors; D000375:Aging; D000818:Animals; D066193:Cervical Cord / Q000033:anatomy & histology*; D002574:Cervical Vertebrae / Q000033:anatomy & histology*; D005260:Female; D008279:Magnetic Resonance Imaging; D051381:Rats; D011916:Rats, Inbred F344; D013119:Spinal Cord Injuries / Q000473:pathology
keywords: aging; injury; rat; spinal column; spinal cord