Traumatic brain injury causes delayed motor and cognitive impairment in a mutant mouse strain known to exhibit delayed Wallerian degeneration.
Delayed Wallerian degeneration after neuronal injury is a feature of the C57BL/Wld(s) mouse mutant. In the present study, we examined the effect of unilateral controlled cortical impact (CCI) on motor and cognitive performance in C57BL/6 and C57BL/Wld(s) mice. Performance on a beam-walking task was impaired in both injured groups over the first 3 weeks; however, between 28 and 35 days post injury, C57BL/6 mice continued to improve whereas C57BL/Wld(s) mice showed increased footfaults. In a spatial learning task, C57BL/Wld(s) animals performed consistently better than C57BL/6 mice when tested 7-10 days and 14-17 days following CCI. C57BL/Wld(s) mice also demonstrated improved working memory performance as compared with C57BL/6 mice when trained on days 21-22 after injury; this effect was lost on days 23 and 24, and was not evident in other animals tested in the same task at 28-31 days following injury. These results indicate a marked delay in motor and cognitive impairment following CCI in C57BL/Wld(s) mice compared with injured C57BL/6 controls. This is consistent with previous work showing delayed temporal evolution of neuronal degeneration in C57BL/Wld(s) mice and suggests CCI may be a suitable model for examining the functional consequences of traumatic brain injury (TBI) in genetically altered mice.
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Georgetown Institute for Cognitive and Computational Sciences, Georgetown University Medical Center, Washington, DC 20007-2197, USA.
Faden
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D000818:Animals; D001930:Brain Injuries / Q000150:complications*; D003072:Cognition Disorders / Q000209:etiology*; D005552:Forelimb / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008818:Mice, Neurologic Mutants; D009069:Movement Disorders / Q000209:etiology* / Q000503:physiopathology; D004856:Postural Balance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D013550:Swimming; D013997:Time Factors; D014855:Wallerian Degeneration / Q000150:complications* / Q000503:physiopathology; D014949:Wounds, Nonpenetrating / Q000150:complications*