P1‐273: Predictive diagnostic accuracy of 123 I‐FP‐CIT spect in possible dementia with Lewy bodies: A 12‐month follow‐up study

administered imaging agent that will provide an early measure of plaque or amyloid aggregate burden associated with AD. Methods: The Pronucleon peptide was first examined as an ex vivo stain for amyloid plaques. We have since administered (intranasally) Pronucleon peptides in hAPP transgenic mice that develop extensive plaque pathology. Sections from these mice were subjected to ex vivo analyses including fluorescence, Thioflavin S staining, anti-amyloid staining and anti-GFAP staining. The Pronucleon peptides contain fluorescent tags that are sensitive to beta amyloid conformational states and results in the ability to image beta amyloid aggregates with a fluorescent microscope. Results: Ex vivo administration of the Pronucleon peptide to tissue section from transgenic mice demonstrates that the peptide labels plaque like material. These, ex vivo, plaque-like images co merge with Thioflavin S staining. Intransal, in vivo, administration of the fluorescent Pronucleon peptide labels plaques in the hippocampus and cortex of transgenic mice. Fluorescent structures had plaque like morphology and co merged with antiamyloid antibody or Thioflavin S staining. A significant positive correlation was observed between Pronucleon peptide staining and Thioflavin S staining. Conclusions: These data suggest that the Pronucleon peptide can efficiently cross the blood brain barrier, label plaques, and may be an effective tool for in vivo imaging.