title: Detection of Alzheimer's disease amyloid-beta plaque deposition by deep brain impedance profiling.
abstract: OBJECTIVE
  Alzheimer disease (AD) is the most common form of neurodegenerative disease in elderly people. Toxic brain amyloid-beta (Aß) aggregates and ensuing cell death are believed to play a central role in the pathogenesis of the disease. In this study, we investigated if we could monitor the presence of these aggregates by performing in situ electrical impedance spectroscopy measurements in AD model mice brains.
  
  
  METHODS
  In this study, electrical impedance spectroscopy measurements were performed post-mortem in APPPS1 transgenic mice brains. This transgenic model is commonly used to study amyloidogenesis, a pathological hallmark of AD. We used flexible probes with embedded micrometric electrodes array to demonstrate the feasibility of detecting senile plaques composed of Aß peptides by localized impedance measurements.
  
  
  RESULTS
  We particularly focused on deep brain structures, such as the hippocampus. Ex vivo experiments using brains from young and old APPPS1 mice lead us to show that impedance measurements clearly correlate with the percentage of Aβ plaque load in the brain tissues. We could monitor the effects of aging in the AD APPPS1 mice model.
  
  
  CONCLUSIONS
  We demonstrated that a localized electrical impedance measurement constitutes a valuable technique to monitor the presence of Aβ-plaques, which is complementary with existing imaging techniques. This method does not require prior Aβ staining, precluding the risk of variations in tissue uptake of dyes or tracers, and consequently ensuring reproducible data collection.
authors: Microsystems Laboratory, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors: Amélie
authors: A
authors: Béduer
authors: Pierre
authors: P
authors: Joris
authors: Sébastien
authors: S
authors: Mosser
authors: Patrick C
authors: PC
authors: Fraering
authors: Philippe
authors: P
authors: Renaud
mesh_terms: D000544:Alzheimer Disease / Q000175:diagnosis* / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003943:Diagnostic Techniques, Neurological / Q000295:instrumentation; D058266:Dielectric Spectroscopy / Q000295:instrumentation / Q000379:methods*; D005260:Female; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D058225:Plaque, Amyloid / Q000378:metabolism*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution