OBJECTIVE: To examine the possible contribution of inflammation and breakdown of the blood-brain barrier in the central nervous system (CNS) of physiologically aged rats showing cognitive decline. METHODS: Young (3- to 6-month-old) and aged (24- to 30-month-old) Wistar rats were assessed by the novel object recognition test. Vascular and inflammatory changes in the CNS were investigated in whole-mount preparations or sections of retinas from young adult or aged male Wistar rats. RESULTS: Aged rats showed a significant impairment in short-term memory compared with young adults. Deterioration of blood-retinal barrier function in aged rats was evidenced by leakage of intravascular tracer into the retinal parenchyma and reduced immunoreactivity for the tight junctional protein, occludin. Immunohistochemistry revealed the presence of major histocompatibility complex (MHC) class II-positive resident microglia, activated T cells, and monocyte-like cells in the retinal parenchyma of aged rats only. Microglia positive for the ED1 antigen, indicative of phagocytic activity, were also observed in these retinas. CONCLUSION: Breakdown of the blood-retinal barrier, MHC class II expression, microglial activation, and trafficking of activated T cells are associated with physiological aging. Such changes in the CNS may contribute to the pathogenesis of age-related cognitive decline.
OBJECTIVE: To examine the possible contribution of inflammation and breakdown of the blood-brain barrier in the central nervous system (CNS) of physiologically aged rats showing cognitive decline. METHODS: Young (3- to 6-month-old) and aged (24- to 30-month-old) Wistar rats were assessed by the novel object recognition test. Vascular and inflammatory changes in the CNS were investigated in whole-mount preparations or sections of retinas from young adult or aged male Wistar rats. RESULTS: Aged rats showed a significant impairment in short-term memory compared with young adults. Deterioration of blood-retinal barrier function in aged rats was evidenced by leakage of intravascular tracer into the retinal parenchyma and reduced immunoreactivity for the tight junctional protein, occludin. Immunohistochemistry revealed the presence of major histocompatibility complex (MHC) class II-positive resident microglia, activated T cells, and monocyte-like cells in the retinal parenchyma of aged rats only. Microglia positive for the ED1 antigen, indicative of phagocytic activity, were also observed in these retinas. CONCLUSION: Breakdown of the blood-retinal barrier, MHC class II expression, microglial activation, and trafficking of activated T cells are associated with physiological aging. Such changes in the CNS may contribute to the pathogenesis of age-related cognitive decline.
Authors: Daniel J Dauer; Zhi Huang; Grace K Ha; Jeremy Kim; David Khosrowzadeh; John M Petitto Journal: Brain Behav Immun Date: 2010-08-19 Impact factor: 7.217
Authors: Alaina M Reagan; Xiaowu Gu; Sijalu Paudel; Nicole M Ashpole; Michelle Zalles; William E Sonntag; Zoltan Ungvari; Anna Csiszar; Laura Otalora; Willard M Freeman; Michael B Stout; Michael H Elliott Journal: Neurobiol Aging Date: 2018-07-10 Impact factor: 4.673
Authors: Mausam R Damani; Lian Zhao; Aurora M Fontainhas; Juan Amaral; Robert N Fariss; Wai T Wong Journal: Aging Cell Date: 2010-12-29 Impact factor: 9.304
Authors: Jena J Steinle; Sheena Sharma; Christopher P Smith; Lisa S McFayden-Ketchum Journal: J Gerontol A Biol Sci Med Sci Date: 2009-01-30 Impact factor: 6.053