title: β-Amyloid binding in elderly subjects with declining or stable episodic memory function measured with PET and [¹¹C]AZD2184.
abstract: OBJECTIVE
  Cognitive decline has been suggested as an early marker for later onset of Alzheimer's disease. We therefore explored the relationship between decline in episodic memory and β-amyloid using positron emission tomography (PET) and [(11)C]AZD2184, a radioligand with potential to detect low levels of amyloid deposits.
  
  
  METHODS
  Healthy elderly subjects with declining (n = 10) or stable (n = 10) episodic memory over 15 years were recruited from the population-based Betula study and examined with PET. Brain radioactivity was measured after intravenous administration of [(11)C]AZD2184. The binding potential BP ND was calculated using linear graphical analysis with the cerebellum as reference region.
  
  
  RESULTS
  The binding of [(11)C]AZD2184 in total grey matter was generally low in the declining group, whereas some binding could be observed in the stable group. Mean BP ND was significantly higher in the stable group compared to the declining group (p = 0.019). An observation was that the three subjects with the highest BP ND were ApoE ε4 allele carriers.
  
  
  CONCLUSIONS
  We conclude that cognitive decline in the general population does not seem to stand by itself as an early predictor for amyloid deposits.
authors.affiliation: Centre for Psychiatry Research, Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden, patrik.mattsson@ki.se.
authors.forename: Patrik
authors.initials: P
authors.lastname: Mattsson
authors.forename: Anton
authors.initials: A
authors.lastname: Forsberg
authors.forename: Jonas
authors.initials: J
authors.lastname: Persson
authors.forename: Lars
authors.initials: L
authors.lastname: Nyberg
authors.forename: Lars-Göran
authors.initials: LG
authors.lastname: Nilsson
authors.forename: Christer
authors.initials: C
authors.lastname: Halldin
authors.forename: Lars
authors.initials: L
authors.lastname: Farde
mesh_terms: D000368:Aged; D000631:Aminopyridines / Q000493:pharmacokinetics*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D052160:Benzothiazoles / Q000493:pharmacokinetics*; D002250:Carbon Radioisotopes / Q000493:pharmacokinetics; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000378:metabolism*; D061212:Memory, Episodic; D008875:Middle Aged; D057054:Molecular Imaging / Q000379:methods*; D049268:Positron-Emission Tomography / Q000379:methods*; D011485:Protein Binding; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: C539976:2-(6-(methylamino)pyridin-3-yl)-1,3-benzothiazol-6-ol; D000631:Aminopyridines; D016229:Amyloid beta-Peptides; D052160:Benzothiazoles; D002250:Carbon Radioisotopes; D019275:Radiopharmaceuticals