title: Detrimental effects of a high fat/high cholesterol diet on memory and hippocampal markers in aged rats.
abstract: High fat diets have detrimental effects on cognitive performance, and can increase oxidative stress and inflammation in the brain. The aging brain provides a vulnerable environment to which a high fat diet could cause more damage. We investigated the effects of a high fat/high cholesterol (HFHC) diet on cognitive performance, neuroinflammation markers, and phosphorylated Tau (p-Tau) pathological markers in the hippocampus of Young (4-month old) versus Aged (14-month old) male rats. Young and Aged male Fisher 344 rats were fed a HFHC diet or a normal control diet for 6 months. All animals underwent cognitive testing for 12days in a water radial arm maze to assess spatial and working reference memory. Hippocampal tissue was analyzed by immunohistochemistry for structural changes and inflammation, and Western blot analysis. Young and Aged rats fed the HFHC diet exhibited worse performance on a spatial working memory task. They also exhibited significant reduction of NeuN and calbindin-D28k immunoreactivity as well as an increased activation of microglial cells in the hippocampal formation. Western blot analysis of the hippocampus showed higher levels of p-Tau S202/T205 and T231 in Aged HFHC rats, suggesting abnormal phosphorylation of Tau protein following the HFHC diet exposure. This work demonstrates HFHC diet-induced cognitive impairment with aging and a link between high fat diet consumption and pathological markers of Alzheimer's disease.
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Ledreux
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Section of Neurodegeneration, Karolinska Institutet, Stockholm, Sweden; Department of Neurology, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
authors.forename: Xiuzhe
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Neurobiology, Care Sciences and Society, Section of Neurodegeneration, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Marianne
authors.initials: M
authors.lastname: Schultzberg
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA. Electronic address: granholm@musc.edu.
authors.forename: Ann-Charlotte
authors.initials: AC
authors.lastname: Granholm
authors.affiliation: Department of Neurosciences, Medical University of South Carolina, Charleston, SC, USA.
authors.forename: Linnea R
authors.initials: LR
authors.lastname: Freeman
mesh_terms: D000375:Aging; D000818:Animals; D064092:Calbindin 1 / Q000378:metabolism; D002784:Cholesterol / Q000009:adverse effects*; D059305:Diet, High-Fat / Q000009:adverse effects*; D004660:Encephalitis / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism* / Q000473:pathology; D008297:Male; D008570:Memory, Short-Term; D017628:Microglia / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D010766:Phosphorylation; D017966:Pyramidal Cells / Q000473:pathology; D051381:Rats; D065852:Spatial Memory; D016875:tau Proteins / Q000378:metabolism
chemical_list: D064092:Calbindin 1; C489787:MAP2 protein, rat; C558298:Mapt protein, mouse; D008869:Microtubule-Associated Proteins; D016875:tau Proteins; D002784:Cholesterol
keywords: Aging; Cognition; Hippocampus; Spatial memory; Tau phosphorylation