Quantitative Imaging of Regional Cerebral Protein Synthesis in Clinical Alzheimer's Disease by [C]Leucine PET.

Purpose: Protein synthesis is essential to maintain integrity and function of the human brain, and protein synthesis is associated specifically with the formation of long-term memory. Experimental and clinical observations indicate that this process is disturbed in Alzheimer's dementia and other neurodegenerative diseases. In-vivo investigation with positron emission tomography (PET) using [C]leucine provides a unique possibility to measure regional cerebral protein synthesis (rCPS) rates in human brain and to determine whether it is altered in Alzheimer's disease (AD), and thus may provide a target for future therapeutic interventions.

Structural and metabolic correlates of neuropsychological profiles in multiple system atrophy and Parkinson's disease.

Background: Despite increased recognition of cognitive impairment in Multiple System Atrophy (MSA), its neuroanatomical correlates are not well defined. We aimed to explore cognitive profiles in MSA with predominant parkinsonism (MSA-P) and Parkinson's disease (PD) and their relationship to frontostriatal structural and metabolic changes.

Methods: Detailed clinical and neuropsychological evaluation was performed together with diffusion tensor imaging (DTI) and [F]-fluoro-deoxyglucose positron emission tomography ([F]-FDG-PET) in patients with MSA-P (n = 11) and PD (n = 11).

Measurement of Protein Synthesis Rate in Rat by [C]Leucine PET Imaging: Application to the TgF344-AD Model of Alzheimer's Disease.

Long-term memory requires stable protein synthesis and is altered in Alzheimer's disease (AD). This study aimed to implement a method to measure the cerebral protein synthesis rate (PSR) with [C]leucine PET in vivo in rats and evaluate potential PSR alterations longitudinally (6, 12 and 18 months old) in the TgF344-AD rat model of AD. Wistar, wild-type (WT) and TgF344-AD rats (TG) were scanned for 60 min with [C]leucine.

Amyloid-β and APOE genotype predict memory decline in cognitively unimpaired older individuals independently of Alzheimer's disease polygenic risk score.

Background: What combination of risk factors for Alzheimer's disease (AD) are most predictive of cognitive decline in cognitively unimpaired individuals remains largely unclear. We studied associations between APOE genotype, AD-Polygenic Risk Scores (AD-PRS), amyloid-β pathology and decline in cognitive functioning over time in a large sample of cognitively unimpaired older individuals.

Methods: We included 276 cognitively unimpaired older individuals (75 ± 10 years, 63% female) from the EMIF-AD PreclinAD cohort.

Evaluation of in vivo staging of amyloid deposition in cognitively unimpaired elderly aged 78-94.

Amyloid-beta (Aβ) deposition is common in cognitively unimpaired (CU) elderly >85 years. This study investigated amyloid distribution and evaluated three published in vivo amyloid-PET staging schemes from a cognitively unimpaired (CU) cohort aged 84.9 ± 4.