Postmortem Brain Imaging in Alzheimer’s Disease and Related Dementias: The South Texas Alzheimer’s Disease Research Center Repository

Abstract

Background: Neuroimaging bears the promise of providing new biomarkers that could refine the diagnosis of dementia. Still, obtaining the pathology data required to validate the relationship between neuroimaging markers and neurological changes is challenging. Existing data repositories are focused on a single pathology, are too small, or do not precisely match neuroimaging and pathology findings. Objective: The new data repository introduced in this work, the South Texas Alzheimer’s Disease research center repository, was designed to address these limitations. Our repository covers a broad diversity of dementias, spans a wide age range, and was specifically designed to draw exact correspondences between neuroimaging and pathology data. Methods: Using four different MRI sequences, we are reaching a sample size that allows for validating multimodal neuroimaging biomarkers and studying comorbid conditions. Our imaging protocol was designed to capture markers of cerebrovascular disease and related lesions. Quantification of these lesions is currently underway with MRI-guided histopathological examination. Results: A total of 139 postmortem brains (70 females) with mean age of 77.9 years were collected, with 71 brains fully analyzed. Of these, only 3% showed evidence of AD-only pathology and 76% had high prevalence of multiple pathologies contributing to clinical diagnosis. Conclusion: This repository has a significant (and increasing) sample size consisting of a wide range of neurodegenerative disorders and employs advanced imaging protocols and MRI-guided histopathological analysis to help disentangle the effects of comorbid disorders to refine diagnosis, prognosis and better understand neurodegenerative disorders.

Bridging the Gap: Multi-Omics Profiling of Brain Tissue in Alzheimer’s Disease and Older Controls in Multi-Ethnic Populations

“…Autopsied brain tissue is hemisected, with the left hemibrain (typically) fixed in 10% neutral-buffered formalin and the right hemibrain (typically) sectioned fresh and preserved at -80°C. Following a minimum 4-week fixation period and postmortem ex vivo magnetic resonance imaging [66], fixed tissue is sectioned and sampled in accordance with National Institute on Aging-Alzheimer's Association Alzheimer's disease (AD) neuropathologic guidelines. For the AMP-AD Diversity Initiative, frozen tissue (approximately 500 mg) was sampled from the anterior caudate, the middle frontal gyrus (Brodmann Area 9 or dorsolateral prefrontal cortex; at the same level as the anterior caudate), and the superior temporal gyrus (at the level of the amygdala) from 6 brain autopsy cases in the Biggs Institute Brain Bank.…”