Center for Quantitative Cancer Imaging, Huntsman Cancer Institute, University of Utah, Salt Lake City, UT, USA.
Department of Psychology (Professor Emeritus), University of Utah, Salt Lake City, UT, USA.
Geroscience. 2019 Aug;41(4):467-481. doi: 10.1007/s11357-019-00089-9. Epub 2019 Aug 31.
Sepsis is a severe systemic inflammatory response to infection associated with acute and chronic neurocognitive consequences, including an increased risk of later-life dementia. In a lipopolysaccharide-induced rat sepsis model, we have demonstrated neuroinflammation, cortical amyloid-beta plaque deposition, and increased whole brain levels of phosphorylated tau. Hippocampal abnormalities, particularly those of the dentate gyrus, are seen in Alzheimer's disease and age-related memory loss. The focus of this study was to determine whether Aβ plaques and phosphorylated tau aggregates occur in the hippocampus as a consequence of lipopolysaccharide administration, and whether behavioral abnormalities related to the hippocampus, particularly the dentate gyrus, can be demonstrated. Male Sprague Dawley rats received an intraperitoneal injection of 10 mg/kg of lipopolysaccharide endotoxin. Control animals received a saline injection. Seven days post injection, Aβ plaques and phosphorylated tau in the hippocampus were quantified following immunostaining. Behavioral tests that have previously been shown to result in specific deficits in dentate gyrus-lesioned rats were administered. Lipopolysaccharide treatment results in the deposition of beta amyloid plaques and intracellular phosphorylated tau in the hippocampus, including the dorsal dentate gyrus. Lipopolysaccharide treatment resulted in behavioral deficits attributable to the dorsal dentate gyrus, including episodic-like memory function that primarily involves spatial, contextual, and temporal orientation and integration. Lipopolysaccharide administration results in hippocampal deposition of amyloid-beta plaques and intracellular phosphorylated tau and results in specific behavioral deficits attributable to the dorsal dentate gyrus. These findings, if persistent, could provide a basis for the higher rate of dementia in longitudinal studies of sepsis survivors.
败血症是一种严重的全身炎症反应,与感染相关,可导致急性和慢性神经认知后果,包括晚年痴呆症的风险增加。在脂多糖诱导的大鼠败血症模型中,我们已经证明了神经炎症、皮质淀粉样β斑块沉积以及整个大脑中磷酸化tau 水平的增加。阿尔茨海默病和与年龄相关的记忆丧失中可见海马体异常,特别是齿状回的异常。本研究的重点是确定脂多糖给药是否会导致海马体中出现 Aβ 斑块和磷酸化 tau 聚集,以及是否可以证明与海马体相关的行为异常,特别是齿状回。雄性 Sprague Dawley 大鼠接受 10mg/kg 脂多糖内毒素的腹腔注射。对照动物接受生理盐水注射。注射后 7 天,通过免疫染色定量海马体中的 Aβ 斑块和磷酸化 tau。进行了先前已显示导致齿状回损伤大鼠特定缺陷的行为测试。脂多糖处理导致海马体中β淀粉样斑块和细胞内磷酸化 tau 的沉积,包括背齿状回。脂多糖处理导致与背齿状回相关的行为缺陷,包括主要涉及空间、上下文和时间定向和整合的类似发作的记忆功能。脂多糖给药导致海马体中淀粉样β斑块和细胞内磷酸化 tau 的沉积,并导致与背齿状回相关的特定行为缺陷。如果这些发现持续存在,可能为败血症幸存者的纵向研究中痴呆症发生率较高提供依据。