TY - JOUR AU - Endepols, Heike AU - Anglada-Huguet, Marta AU - Mandelkow, Eckhard AU - Schmidt, Yannick AU - Krapf, Philipp AU - Zlatopolskiy, Boris D AU - Neumaier, Bernd AU - Mandelkow, Eva Maria AU - Drzezga, Alexander TI - Assessment of the In Vivo Relationship Between Cerebral Hypometabolism, Tau Deposition, TSPO Expression, and Synaptic Density in a Tauopathy Mouse Model: a Multi-tracer PET Study. JO - Molecular neurobiology VL - 59 SN - 0893-7648 CY - Totowa, NJ PB - Humana Press M1 - DZNE-2022-00497 SP - 3402-3413 PY - 2022 N1 - (CC BY 4.0) AB - Cerebral glucose hypometabolism is a typical hallmark of Alzheimer's disease (AD), usually associated with ongoing neurodegeneration and neuronal dysfunction. However, underlying pathological processes are not fully understood and reproducibility in animal models is not well established. The aim of the present study was to investigate the regional interrelation of glucose hypometabolism measured by [18F]FDG positron emission tomography (PET) with various molecular targets of AD pathophysiology using the PET tracers [18F]PI-2620 for tau deposition, [18F]DPA-714 for TSPO expression associated with neuroinflammation, and [18F]UCB-H for synaptic density in a transgenic tauopathy mouse model. Seven-month-old rTg4510 mice (n = 8) and non-transgenic littermates (n = 8) were examined in a small animal PET scanner with the tracers listed above. Hypometabolism was observed throughout the forebrain of rTg4510 mice. Tau pathology, increased TSPO expression, and synaptic loss were co-localized in the cortex and hippocampus and correlated with hypometabolism. In the thalamus, however, hypometabolism occurred in the absence of tau-related pathology. Thus, cerebral hypometabolism was associated with two regionally distinct forms of molecular pathology: (1) characteristic neuropathology of the Alzheimer-type including synaptic degeneration and neuroinflammation co-localized with tau deposition in the cerebral cortex, and (2) pathological changes in the thalamus in the absence of other markers of AD pathophysiology, possibly reflecting downstream or remote adaptive processes which may affect functional connectivity. Our study demonstrates the feasibility of a multitracer approach to explore complex interactions of distinct AD-pathomechanisms in vivo in a small animal model. The observations demonstrate that multiple, spatially heterogeneous pathomechanisms can contribute to hypometabolism observed in AD mouse models and they motivate future longitudinal studies as well as the investigation of possibly comparable pathomechanisms in human patients. KW - Alzheimer Disease: diagnostic imaging KW - Alzheimer Disease: metabolism KW - Animals KW - Brain: diagnostic imaging KW - Brain: metabolism KW - Disease Models, Animal KW - Glucose KW - Humans KW - Mice KW - Mice, Transgenic KW - Positron-Emission Tomography: methods KW - Receptors, GABA: metabolism KW - Reproducibility of Results KW - Tauopathies: diagnostic imaging KW - Tauopathies: metabolism KW - tau Proteins: metabolism KW - Alzheimer’s disease (Other) KW - Cerebral hypometabolism (Other) KW - Microglial activation (Other) KW - Neuroinflammation (Other) KW - Small animal PET (Other) KW - Synaptic density (Other) KW - Tau (Other) LB - PUB:(DE-HGF)16 C2 - pmc:PMC9148291 C6 - pmid:35312967 DO - DOI:10.1007/s12035-022-02793-8 UR - https://pub.dzne.de/record/163758 ER -