title: Locomotor recovery and mechanical hyperalgesia following spinal cord injury depend on age at time of injury in rat.
abstract: We tested the effect of age at the time of spinal cord injury (SCI) on locomotor recovery, in open field tests, and mechanical hyperalgesia, using paw withdrawal frequency (PWF) in response to noxious mechanical stimuli, in male Sprague-Dawley rats after spinal hemisection at T13 in young (40 days), adult (60 days) and middle-age (1 year) groups. Behavioral outcomes were measured weekly for 4 weeks in both SCI and sham groups. Following SCI, the young and adult groups recovered significantly more locomotor function, at a more rapid rate, than did the middle-age group. The PWF of the young group was significantly increased, the adult group was significantly decreased, and the middle-age group showed no significant change in fore- and hindlimbs when compared to other age groups, pre-injury and sham controls. These results support age-dependent behavioral outcomes after SCI.
authors.affiliation: Department of Anatomy and Neurosciences, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1043, USA.
authors.forename: Young Seob
authors.initials: YS
authors.lastname: Gwak
authors.forename: Bryan C
authors.initials: BC
authors.lastname: Hains
authors.forename: Kathia M
authors.initials: KM
authors.lastname: Johnson
authors.forename: Claire E
authors.initials: CE
authors.lastname: Hulsebosch
mesh_terms: D000367:Age Factors; D000818:Animals; D001522:Behavior, Animal; D005552:Forelimb / Q000503:physiopathology; D006614:Hindlimb / Q000503:physiopathology; D006930:Hyperalgesia / Q000209:etiology*; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010147:Pain Measurement; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000503:physiopathology*; D013997:Time Factors; D014110:Touch