title: Does Microglial Activation Influence Hippocampal Volume and Neuronal Function in Alzheimer's Disease and Parkinson's Disease Dementia?
abstract: BACKGROUND
  The influence of neuroinflammation on neuronal function and hippocampal atrophy in Alzheimer's disease (AD) and Parkinson's disease dementia (PDD) is still unclear.
  
  
  OBJECTIVE
  Here we investigated whether microglial activation measured by [11C]PK11195 PET is associated with neuronal function measured by cerebral glucose metabolic rate (rCMRGlc) using FDG-PET and hippocampal volume measurements.
  
  
  METHODS
  We enrolled 25 subjects (9 PDD, 8 AD, and 8 controls) who underwent PET scans with [11C](R)PK11195, [18F]FDG, and volumetric MRI scanning.
  
  
  RESULTS
  SPM correlation analysis in AD and PDD showed a negative correlation between hippocampal volume and microglial activation within hippocampus or parahippocampus and with cortical and subcortical areas of projections from hippocampus, while there was a positive correlation between rCMRGlc in cortical and subcortical areas of projections from hippocampus and hippocampal volume. Hippocampal volume was significantly reduced in AD compared to controls but not in PDD.
  
  
  CONCLUSIONS
  These findings indicate that microglial activation inversely correlated with hippocampal volume and hippocampal rCMRGlc in neurodegenerative diseases with dementia, providing further evidence for the central role of microglial activation in neurodegenerative diseases.
authors.affiliation: Neurology Imaging Unit, Imperial College London, London, UK.
authors.forename: Grazia D
authors.initials: GD
authors.lastname: Femminella
authors.affiliation: Neurology Imaging Unit, Imperial College London, London, UK.
authors.forename: Siddharth
authors.initials: S
authors.lastname: Ninan
authors.affiliation: Neurology Imaging Unit, Imperial College London, London, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Atkinson
authors.affiliation: Neurology Imaging Unit, Imperial College London, London, UK.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Fan
authors.affiliation: Neurology Imaging Unit, Imperial College London, London, UK.|Department of Nuclear Medicine, Aarhus University, Denmark.
authors.forename: David J
authors.initials: DJ
authors.lastname: Brooks
authors.affiliation: Neurology Imaging Unit, Imperial College London, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Edison
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D000970:Antineoplastic Agents / Q000493:pharmacokinetics; D001931:Brain Mapping; D003071:Cognition; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology*; D006801:Humans; D007546:Isoquinolines / Q000493:pharmacokinetics; D008279:Magnetic Resonance Imaging; D008297:Male; D017628:Microglia / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D008875:Middle Aged; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000473:pathology*; D049268:Positron-Emission Tomography; D011569:Psychiatric Status Rating Scales; D013494:Supranuclear Palsy, Progressive / Q000000981:diagnostic imaging / Q000473:pathology*
chemical_list: D000970:Antineoplastic Agents; D007546:Isoquinolines; D019788:Fluorodeoxyglucose F18; C037850:PK 11195
keywords: Alzheimer’s disease; PET; Parkinson’s disease with dementia; neuroinflammation; volumetric MRI