O1‐02‐05: A novel positron emission tomography contrast agent targeting cathepsin d shows preferential in vivo retention in an Alzheimer's disease mouse model

(8465.76639.2 mm), while it was not significantly different in PDD subjects (7568.761095.4mm) compared to controls. [11C](R)PK11195 BP was significantly increased in all cortical ROIs in both AD and PDD subjects compared to controls; the regional cortical rCMRGlc was significantly reduced in AD and PDD compared to controls in almost all ROIs. SPM Correlation between [11C](R)PK11195 BP, rCMRGlc and hippocampal volume indicated that both in AD and PDD increased glial activation, as well as reduced glucose metabolism, show a negative and positive correlation, respectively, with hippocampal volume (Figure 1). The spatial agreement between local and distant glial activation in the cortical projections and atrophy in hippocampus supports the theory that chronically activated glial cells might be one of the effectors of neurodegenerative processes. Conclusions: We have shown that glial activation, as assessed by [11C](R)PK11195 PET, inversely correlates with hippocampal volume in neurodegenerative diseases with dementia, providing further evidence for the central role of microglial activation in neurodegenerative diseases like AD and PDD.