Alzheimer & Parkinson

Alzheimer's disease has widespread effects on brain structure, function and behavior, but we lack a systematic dissection of its impact across hundreds of forebrain and brainstem regions. Here, using diffusion tensor MRI at 25 µm, we mapped the global consequences of mutations in APP and PSEN1 across 231 regions of interest (ROIs) in male and female 5×FAD BXD hybrid mice at 14 months. Over half of the ROIs change in volume along rostrocaudal and mediolateral axes of the CNS, with unexpected...

Neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD) are clinically heterogeneous, hampering the success of nonselective treatment strategies. Here we apply a transformer-based unsupervised clustering framework to longitudinal electronic health record data from over 100,000 patients across two UK cohorts, Clinical Practice Research Datalink Aurum and UK Biobank, to identify, validate and characterize subtypes of AD and PD. We uncover five reproducible subtypes...

The misfolding and accumulating α-synuclein (αSyn) is a central pathological hallmark of various neurodegenerative diseases, including Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy. Under physiological conditions, αSyn essential for normal synaptic functions primarily through its regulation of synaptic vesicle trafficking, clustering, and neurotransmitter release. However, in disease states, the accumulation of pathological αSyn disrupts intracellular proteostasis,...

The existence of human hippocampal neurogenesis has long been disputed^(1-12) and its relevance in cognition remains unknown. Recent studies have established the presence of proliferating progenitors and immature neurons and a reduction in the latter in Alzheimer's disease (AD)^(11,13). However, their origin and the molecular networks that regulate neurogenesis and function are poorly understood. Here we studied human post-mortem hippocampi obtained from different cohorts: young adults with...

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Increased life expectancy brought about by improved healthcare and lifestyle has heightened the challenge of neurodegenerative disorders like Alzheimer's disease (AD) and other age-related disorders. Neurodegeneration is known to be accompanied by loss of memory, changes in brain morphology, and neuroinflammation, and multiple factors contribute to the progression and pathogenesis of the condition. Of these factors, metabolic dysregulation is known to influence the process, but the precise...

Processing bodies (P-bodies) are conserved ribonucleoprotein granules central to RNA metabolism across eukaryotes. Although the mechanisms underlying their assembly are well understood, the pathways governing their selective turnover remain unclear. Here, we identify the conserved decapping proteins Enhancer of mRNA decapping 4 (EDC4) and decapping protein 1 (DCP1) as a selective autophagy receptor pair responsible for P-body turnover in the model plant Marchantia polymorpha. MpEDC4 engages ATG8...

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The brain continuously integrates rapidly changing visual input across eye movements to maintain stable perception, yet the precise mechanisms underpinning dynamic working memory and how these break down in brain diseases remain unclear. We developed a novel eye-tracking paradigm and computational models to investigate how spatial and colour information are updated across saccades in the human brain. Our findings reveal that saccades selectively impair spatial but not colour memory....

Synaptic Plasticity pertains to the synapse's tendency to adapt fresh information and is a crucial step in the establishment of brain circuits that aid in memory formation. It has become one of the most intensively researched topics in all of neuroscience. Pieces of evidence are accumulating that synaptopathy (altered synaptic plasticity) mechanisms contribute to Alzheimer's disease (AD) and Parkinson's disease (PD). Toxins responsible for synaptopathy and aberrant neurotransmitter (NT) release...

This review synthesizes three decades of evidence regarding the role of cytochrome P450 enzymes (CYPs) in Parkinson's disease (PD), revealing their multifaceted roles beyond traditional pesticide metabolism. While CYP2D6 remains the most studied enzyme due to its association with PD risk in poor metabolizer phenotypes and its dual role in dopamine (DA) synthesis (directly via tyramine hydroxylation and indirectly through precursor demethylation), recent research has highlighted less-studied CYPs...

Normative models are increasingly used to characterize individual-level brain deviations in neuroimaging studies, but their performance depends heavily on the reference sample used for training or adaptation. In this study, we systematically investigated how sample size and covariate composition of the reference cohort influence model fit, deviation estimates, and clinical readouts in Alzheimer's disease (AD). Using a discovery dataset (OASIS-3, n = 1032), we trained models on healthy control...

With the introduction of adaptive deep brain stimulation (aDBS) for Parkinson's disease, new questions emerge regarding who, why, and how to treat. This paper outlines the pathophysiological rationale for aDBS, which provides real-time modulation of the stimulation amplitude based on subthalamic beta (range 13-30 Hz) activity and related physiomarkers. We review clinical evidence comparing aDBS with conventional DBS in terms of motor improvement, side-effect reduction, energy efficiency, and...

Early intervention is the most effective strategy to impede the progression of Alzheimer's disease (AD), depending on the identification of early diagnostic biomarkers. Here, we isolate neuron-derived exosomes (NDEs) from plasma of familial AD (FAD), presymptomatic FAD (pre-FAD), and healthy controls (cognitively normal [CN]), followed by label-free liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. A specific peptide from protein phosphatase 2 regulatory subunit B'β (PPP2R5C)...

Dysfunction of transactive response DNA-binding protein 43 (TDP-43) drives neurodegeneration in amyotrophic lateral sclerosis (ALS) and Alzheimer's disease (AD), in part through inducing aberrant RNA splicing. However, whether such mis-splicing yields stable, pathogenic proteins remains unclear. Here, we identify a TDP-43-repressed cryptic exon in Protein kinase N1 (PKN1), designated PKN1-5a1, which is activated in ALS patient brains and introduces a premature termination codon. This aberrant...

The APOE-ε4 allele is the strongest genetic risk factor for late-onset Alzheimer's disease. However, APOE-ε4 is not deterministic, highlighting the need to identify additional genetic and environmental factors. APOE-ε4 has been linked to accelerated cognitive decline, so we sought to investigate genetic factors that modify APOE-ε4-associated cognitive decline. We conduct cross-ancestry APOE-ε4-stratified and interaction GWAS using harmonized cognitive data from 32,778 participants, including...

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The nonreceptor Abelson (Abl) tyrosine kinases have been implicated as key drivers of initiation and progression in Parkinson's disease (PD). Risvodetinib, a potent, brain-penetrant, selective inhibitor of the nonreceptor Abl kinases c-Abl1 and c-Abl2/Arg (collectively, c-Abl), was evaluated in a randomized, double-blind, placebo-controlled phase 2a trial ('the 201 Trial') using once-daily 50 mg, 100 mg, 200 mg or placebo in 137 participants with early, untreated PD. The primary end points in...

Tauopathies are neurodegenerative diseases marked by pathological tau aggregation. While disease-specific folds of insoluble tau filaments have been established, it remains unclear whether the smaller, earlier species also differ across tauopathies. Here, we characterize these small tau aggregates from postmortem brain of individuals with Alzheimer's disease (AD), progressive supranuclear palsy (PSP), corticobasal degeneration, Pick's disease, and healthy controls. Using two complementary...

CONCLUSIONS: The strength and significance of our study are that it is the first to indicate, on the basis of the α-syn mechanism, that the mean RNFL thickness partly reflects striatal dopamine uptake in the brain, suggesting that the mean RNFL thickness may have a certain value for the early diagnosis of PD.