Heterogeneous tau deposition patterns in the preclinical stage link to domain-specific cognitive deficits.

Introduction: The spatial heterogeneity of tau deposition is closely linked to clinical variants of Alzheimer's disease (AD). Detecting these patterns in the preclinical stage is challenging, but second-generation tau tracers provide a unique opportunity to do so.

Methods: We used independent component analysis (ICA) and tau positron emission tomography (PET) imaging with the 18F-MK6240 tracer in 590 cognitively healthy adults (mean age 66.

Presence of cortical lesions in older persons with multiple sclerosis and association with cognitive function.

Background: Cortical lesions (CL) have been reported and characterized in multiple sclerosis (MS), but their presence and association with cognitive function in older adults with MS (OAMS) have not been evaluated.

Objective: To quantify the presence of CL in OAMS and healthy controls. We hypothesized that compared to controls, OAMS would have more CL, and CL would be associated with worse cognition.

Integration of physio-biochemical, biological and molecular approaches to improve heavy metal tolerance in plants.

Heavy metal toxicity hinders plant growth and development by inducing oxidative stress, decreasing biomass, impairing photosynthesis, and potentially leading to plant death. The inherent defense mechanisms employed by plants, including metal sequestration into vacuoles, phytochelation, cell wall metal adsorption and an enhanced antioxidant system can be improved via various approaches to mitigate heavy metal toxicity. This review primarily outlines plants direct and indirect responses to HM stress and the tolerance mechanisms by which plants combat the toxic effects of metals and metalloids to understand the effective management of HMs and metalloids in the soil system.

Associations between connectivity in functional brain networks and gait speed in older adults with and without multiple sclerosis.

Objective: To assess whether resting-state functional connectivity (RSFC) brain networks are associated with gait speed in a sample of older adults with and without multiple sclerosis (MS).

Methods: Older adults with MS (OAMS: n = 82, mean age = 64.4 ± 4.

Inter-network functional connectivity increases by beta-amyloid and may facilitate the early stage of tau accumulation.

Alzheimer's disease (AD) is pathologically marked by tau tangles and beta-amyloid (Aβ) plaques. It has been hypothesized that Aβ facilitates spread of tau outside of the medial temporal lobe (MTL), but exact mechanism of this facilitation remains unclear. We aimed to test the hypothesis that abnormal Aβ induces an increase in inter-network functional connectivity, which in turn induces early-stage tau elevation in limbic network.

Negative BOLD Responses Surpass Positive Responses in Task Specificity, Reflecting Neural Reconfigurations Better Than Functional Connectivity.

Objective: To investigate whether the Negative BOLD Response (NBR) is more task-specific than the Positive BOLD Response (PBR) during cognitive tasks and to determine whether task-evoked activity reflects brain reconfigurations during different tasks better than functional connectivity.

Methods: Functional Magnetic Resonance Imaging (fMRI) data were collected from 214 participants under 50 years old (152 in Dataset 1 and 62 in Dataset 2) performing twelve cognitive tasks spanning vocabulary, speed of processing, fluid reasoning, and memory domains. Data analysis included subject-level and group-level analyses, focusing on comparing the spatial patterns and task specificity of NBR and PBR through similarity measures using Dice coefficients.

Increased between-network connectivity: A risk factor for tau elevation and disease progression.

One of the pathologic hallmarks of Alzheimer's disease (AD) is neurofibrillary tau tangles. Despite our knowledge that tau typically initiates in the medial temporal lobe (MTL), the mechanisms driving tau to spread beyond MTL remain unclear. Emerging evidence reveals distinct patterns of functional connectivity change during aging and preclinical AD: while connectivity within-network decreases, connectivity between-network increases.

Remote Associations Between Tau and Cortical Amyloid-β Are Stage-Dependent.

Background: Histopathologic studies of Alzheimer's disease (AD) suggest that extracellular amyloid-β (Aβ) plaques promote the spread of neurofibrillary tau tangles. However, these two proteinopathies initiate in spatially distinct brain regions, so how they interact during AD progression is unclear.

Objective: In this study, we utilized Aβ and tau positron emission tomography (PET) scans from 572 older subjects (476 healthy controls (HC), 14 with mild cognitive impairment (MCI), 82 with mild AD), at varying stages of the disease, to investigate to what degree tau is associated with cortical Aβ deposition.

Deep learning combining FDG-PET and neurocognitive data accurately predicts MCI conversion to Alzheimer's dementia 3-year post MCI diagnosis.

Introduction: This study reports a novel deep learning approach to predict mild cognitive impairment (MCI) conversion to Alzheimer's dementia (AD) within three years using whole-brain fluorodeoxyglucose (FDG) positron emission tomography (PET) and cognitive scores (CS).

Methods: This analysis consisted of 150 normal controls (CN), 257 MCI, and 205  AD subjects from ADNI. FDG-PET and CS were obtained at MCI diagnosis to predict AD conversion within three years of MCI diagnosis using convolutional neural networks.

Distinct and joint effects of low and high levels of Aβ and tau deposition on cortical thickness.

Alzheimer's disease (AD) is defined by the presence of Amyloid-β (Aβ),tau, and neurodegeneration (ATN framework) in the human cerebral cortex. Yet, prior studies have suggested that Aβ deposition can be associated with both cortical thinning and thickening. These contradictory results are attributed to small sample sizes, the presence versus absence of tau, and limited detectability in the earliest phase of protein deposition, which may begin in young adulthood and cannot be captured in studies enrolling only older subjects.

Mid-Frontal Theta Modulates Response Inhibition and Decision Making Processes in Emotional Contexts.

Inhibitory control is an integral part of executive functions. In this study, we report event-related spectral perturbation (ERSP) results from 15 healthy adults performing an emotional stop-signal task with the use of happy, disgusted, and neutral emotional faces. Our ERSP results at the group level suggest that changes in low frequency oscillatory power for emotional and neutral conditions start at as early as 200 ms after stimulus onset and 300 ms before button press for successful go trials.

Resting heart rate variability in young women is a predictor of EEG reactions to linguistic ambiguity in sentences.

Recent research has found a relationship between heart rate variability (HRV) and cognitive control mechanisms underlying various experimental tasks. This study explored the interaction between gender and resting-state HRV in brain oscillatory activity during visual recognition of linguistic ambiguity while taking state and trait anxiety scores into account. It is well known that stress or anxiety increases arousal levels, particularly under uncertainty situations.