Increased Amoeboid Microglial Density in the Olfactory Bulb of Parkinson's and Alzheimer's Patients

K.J. Doorn, A. Goudriaan, C. Blits-Huizinga, J.G.J.M. Bol, A.J. Rozemuller, P.V.J.M. Hoogland, P.J. Lucassen, B. Drukarch, W.D.J. van de Berg, A.-M. van Dam

Research output: Contribution to journalArticleAcademicpeer-review

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Abstract

The olfactory bulb (OB) is affected early in both Parkinson's (PD) and Alzheimer's disease (AD), evidenced by the presence of disease-specific protein aggregates and an early loss of olfaction. Whereas previous studies showed amoeboid microglia in the classically affected brain regions of PD and AD patients, little was known about such changes in the OB. Using a morphometric approach, a significant increase in amoeboid microglia density within the anterior olfactory nucleus (AON) of AD and PD patients was observed. These amoeboid microglia were in close apposition to beta-amyloid, hyperphosphorylated tau or alpha-synuclein deposits, but no uptake of pathological proteins by microglia could be visualized. Subsequent analysis showed 1) no correlation between microglia and alpha-synuclein (PD), 2) a positive correlation with beta-amyloid (AD) and 3) a negative correlation with hyperphosphorylated tau (AD). Furthermore, despite the observed pathological alterations in neurite morphology, neuronal loss was not apparent in the AON of both patient groups. Thus, we hypothesize that, in contrast to the classically affected brain regions of AD and PD patients, within the AON rather than neuronal loss, the increased density in amoeboid microglial cells, possibly in combination with neurite pathology, may contribute to functional deficits.
Original languageEnglish
Pages (from-to)152-165
Number of pages14
JournalBrain Pathology
Volume24
Issue number2
Early online date28 Oct 2013
DOIs
Publication statusPublished - Mar 2014

Keywords

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease
  • Amyloid beta-Peptides
  • Cell Count
  • Female
  • Humans
  • Journal Article
  • Male
  • Microglia
  • Middle Aged
  • Neurons
  • Olfactory Bulb
  • Parkinson Disease
  • Research Support, Non-U.S. Gov't
  • alpha-Synuclein
  • tau Proteins

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