Amyloid-beta dynamics correlate with neurological status in the injured human brain

Science. 2008 Aug 29;321(5893):1221-4. doi: 10.1126/science.1161591.


The amyloid-beta peptide (Abeta) plays a central pathophysiological role in Alzheimer's disease, but little is known about the concentration and dynamics of this secreted peptide in the extracellular space of the human brain. We used intracerebral microdialysis to obtain serial brain interstitial fluid (ISF) samples in 18 patients who were undergoing invasive intracranial monitoring after acute brain injury. We found a strong positive correlation between changes in brain ISF Abeta concentrations and neurological status, with Abeta concentrations increasing as neurological status improved and falling when neurological status declined. Brain ISF Abeta concentrations were also lower when other cerebral physiological and metabolic abnormalities reflected depressed neuronal function. Such dynamics fit well with the hypothesis that neuronal activity regulates extracellular Abeta concentration.

MeSH terms

  • Amyloid beta-Peptides / cerebrospinal fluid
  • Amyloid beta-Peptides / metabolism*
  • Brain / metabolism*
  • Brain / physiology
  • Brain Injuries / metabolism*
  • Brain Injuries / physiopathology
  • Extracellular Fluid / metabolism*
  • Glasgow Coma Scale
  • Glucose / metabolism
  • Humans
  • Intracranial Hypertension
  • Lactic Acid / metabolism
  • Microdialysis
  • Peptide Fragments / metabolism
  • Pyruvic Acid / metabolism


  • Amyloid beta-Peptides
  • Peptide Fragments
  • amyloid beta-protein (1-40)
  • amyloid beta-protein (1-42)
  • Lactic Acid
  • Pyruvic Acid
  • Glucose