Biomarkers.

Background: The amygdala is a hotspot for neuropathologies; however, it is unclear 1) which neuropathologies lead to amygdala neurodegeneration, 2) what specific amygdala subnuclei are affected, and 3) if the neuropathologies related to amygdala volume are local (inside the amygdala), or distal (in other regions). We investigate the relationships between different neuropathologies (tau, amyloid-β [Aβ], α-synuclein [α-syn], and transactive response DNA-binding protein 43 [TDP-43]) and amygdala volumes.

Method: We analyzed postmortem data from 73 individuals with and without neurodegenerative diseases (age: 77±11 [45-101] years; 26 [36%] females; 51 [70%] cognitively impaired).

Biomarkers.

Background: The medial temporal lobe (MTL) is the epicenter of both primary and concomitant molecular pathologies in Alzheimer's disease (AD). The intricate anatomy of the MTL has been the subject of extensive study over the past two centuries. However, current PET and MRI AD biomarkers use often crude parcellations of the MTL that have not been sufficiently validated vis-à-vis anatomical ground truth.

Biomarkers.

Background: Hippocampal Sclerosis of aging (HS) refers to age-related selective neuronal loss and gliosis in hippocampal cornu ammonis 1 (CA1) and subiculum that is out of proportion to tau pathology in Alzheimer's Disease (AD). HS is related to cognitive decline and memory impairments separately from other neurodegenerative pathologies. To date, in vivo imaging biomarkers of HS of aging are non-existent, and their development would greatly improve diagnosis and prognosis in memory clinics.

Developing Topics.

Background: The anterior portion of the MTL is one of the first regions targeted by pathology in sporadic Alzheimer's disease (AD) indicating the potential for imaging metrics from this region to serve as valuable imaging biomarkers. However, most existing automated approaches for MTL segmentation do not incorporate anterior MTL subregions, and the few that do fail to account for its complex anatomical variability. Leveraging a unique postmortem dataset consisting of histology and structural MRI scans we aimed to develop an anatomically valid segmentation protocol for anterior entorhinal cortex (ERC), Brodmann Area (BA) 35, and BA36 and apply it for automated MTL segmentation of in vivo 3 tesla (T) MRI.

Alzheimer's Imaging Consortium.

Background: Hippocampal Sclerosis of aging (HS) refers to age-related selective neuronal loss and gliosis in hippocampal cornu ammonis 1 (CA1) and subiculum that is out of proportion to tau pathology in Alzheimer's Disease (AD). HS is related to cognitive decline and memory impairments separately from other neurodegenerative pathologies. To date, in vivo imaging biomarkers of HS of aging are non-existent, and their development would greatly improve diagnosis and prognosis in memory clinics.

Alzheimer's Imaging Consortium.

Background: The amygdala is a hotspot for neuropathologies; however, it is unclear 1) which neuropathologies lead to amygdala neurodegeneration, 2) what specific amygdala subnuclei are affected, and 3) if the neuropathologies related to amygdala volume are local (inside the amygdala), or distal (in other regions). We investigate the relationships between different neuropathologies (tau, amyloid-ß [Aß], a-synuclein [a-syn], and transactive response DNA-binding protein 43 [TDP-43]) and amygdala volumes.

Method: We analyzed postmortem data from 73 individuals with and without neurodegenerative diseases (age: 77±11 [45-101] years; 26 [36%] females; 51 [70%] cognitively impaired).

Alzheimer's Imaging Consortium.

Background: The medial temporal lobe (MTL) is the epicenter of both primary and concomitant molecular pathologies in Alzheimer's disease (AD). The intricate anatomy of the MTL has been the subject of extensive study over the past two centuries. However, current PET and MRI AD biomarkers use often crude parcellations of the MTL that have not been sufficiently validated vis-à-vis anatomical ground truth.

Associations of phosphorylated tau pathology with whole-hemisphere ex vivo morphometry in 7 tesla MRI.

Introduction: Neurodegenerative disorders are associated with different pathologies that often co-occur but cannot be measured specifically with in vivo methods.

Methods: Thirty-three brain hemispheres from donors with an Alzheimer's disease (AD) spectrum diagnosis underwent T2-weighted magnetic resonance imaging (MRI). Gray matter thickness was paired with histopathology from the closest anatomic region in the contralateral hemisphere.

Ex vivo MRI atlas of the human medial temporal lobe: characterizing neurodegeneration due to tau pathology.

Tau neurofibrillary tangle (NFT) pathology in the medial temporal lobe (MTL) is closely linked to neurodegeneration, and is the early pathological change associated with Alzheimer's disease (AD). To elucidate patterns of structural change in the MTL specifically associated with tau pathology, we compared high-resolution ex vivo MRI scans of human postmortem MTL specimens with histology-based pathological assessments of the MTL. MTL specimens were obtained from twenty-nine brain donors, including patients with AD, other dementias, and individuals with no known history of neurological disease.

Neuropeptides in the developing human hippocampus under hypoxic-ischemic conditions.

The perinatal period, sensitive for newborn survival, is also one of the most critical moments in human brain development. Perinatal hypoxia due to reduced blood supply to the brain (ischemia) is one of the main causes of neonatal mortality. Brain damage caused by perinatal hypoxia-ischemia (HI) can lead to neuro- and psychological disorders.