BACKGROUND AND PURPOSE: Although stroke is a disorder associated with aging, experimental studies of stroke are conducted in young adult (2-4-month-old) animals (rat life span, 27-29 months). To determine whether histopathologic changes caused by cerebral infarction would be altered in aged animals, we produced embolic cerebral infarction in 17 aged (23-24-month-old) and 16 young (2-4-month-old) rats. METHODS: The right common carotid artery was irradiated with a laser (632 nm, 200 mW/cm2, 15-20 minutes) after the intravenous injection of the photosensitizing dye Photofrin II (12.5 mg/kg). This produces a nonocclusive platelet thrombus that spontaneously embolizes to the brain. Animals were killed 4 days later. RESULTS: Analysis was done on 142 infarcts, 68 in aged rats and 74 in young rats. Hypercellularity, with infiltration of macrophages, was more common within small infarcts (less than 1 mm) in young than in aged rats (p = 0.002), and hypertrophy of astroglial fibers surrounding the infarcts was more prominent in young rats. Larger infarcts (greater than or equal to 1 mm) were often hypocellular, with a trend toward more macrophages in the periphery of the infarcts in young than in old animals (p = 0.170). CONCLUSIONS: The infiltration of macrophages into cerebral infarcts and the hypertrophy of astroglial fibrils surrounding these infarcts are reduced in the aged rat. These age-related differences emphasize the importance of using appropriately aged animals in experimental models of stroke.
BACKGROUND AND PURPOSE: Although stroke is a disorder associated with aging, experimental studies of stroke are conducted in young adult (2-4-month-old) animals (rat life span, 27-29 months). To determine whether histopathologic changes caused by cerebral infarction would be altered in aged animals, we produced embolic cerebral infarction in 17 aged (23-24-month-old) and 16 young (2-4-month-old) rats. METHODS: The right common carotid artery was irradiated with a laser (632 nm, 200 mW/cm2, 15-20 minutes) after the intravenous injection of the photosensitizing dye Photofrin II (12.5 mg/kg). This produces a nonocclusive platelet thrombus that spontaneously embolizes to the brain. Animals were killed 4 days later. RESULTS: Analysis was done on 142 infarcts, 68 in aged rats and 74 in young rats. Hypercellularity, with infiltration of macrophages, was more common within small infarcts (less than 1 mm) in young than in aged rats (p = 0.002), and hypertrophy of astroglial fibers surrounding the infarcts was more prominent in young rats. Larger infarcts (greater than or equal to 1 mm) were often hypocellular, with a trend toward more macrophages in the periphery of the infarcts in young than in old animals (p = 0.170). CONCLUSIONS: The infiltration of macrophages into cerebral infarcts and the hypertrophy of astroglial fibrils surrounding these infarcts are reduced in the aged rat. These age-related differences emphasize the importance of using appropriately aged animals in experimental models of stroke.
Authors: Guangliang Ding; Quan Jiang; Lian Li; Li Zhang; Zhenggang Zhang; Mei Lu; Qingjiang Li; Steven Gu; James Ewing; Michael Chopp Journal: Stroke Date: 2011-09-08 Impact factor: 7.914
Authors: Kevin M Kelly; Peter I Jukkola; Guo Yin; Eric R Miller; Elena A Kharlamov; Deng-Shan Shiau; Roger Strong; Jaroslaw Aronowski Journal: Epilepsy Res Date: 2018-02-10 Impact factor: 3.045
Authors: Matthew Boyko; Ruslan Kutz; Benjamin F Gruenbaum; Hagit Cohen; Nitsan Kozlovsky; Shaun E Gruenbaum; Yoram Shapira; Alexander Zlotnik Journal: Cogn Affect Behav Neurosci Date: 2013-12 Impact factor: 3.526