Alzheimer & Parkinson

How the memory engram is organized at the cell-assembly level to support not only encoding of learned information but also memory flexibility remains elusive. Here, we propose a novel engram model encoded by two orthogonal learning-recruited neuronal ensembles in the mouse dentate gyrus. Reactivation of the Fos-tagged ensemble promotes memory retrieval, whereas reactivation of the Npas4-dependent ensemble drives forgetting, with manipulation of the forgetting ensemble inversely shifting memory...

The native microbiome influences numerous host processes, including neurological function. However, its impacts on diverse brain cell types remain poorly understood. Here, we performed single-nucleus RNA sequencing on the hippocampus of wild-type, germ-free mice, revealing the microbiome-dependent transcriptional landscape across all major neural cell types. We found conserved impacts on key adaptive immune and neurodegenerative transcriptional pathways. Mono-colonization with select indigenous...

Recent advances in high-throughput technologies have led to an increased generation of biological data across genomics, transcriptomics, proteomics, epigenomics, and metabolomics. However, a major challenge remains: effectively integrating these multi-omics datasets to allow a more holistic understanding of the complex, interconnected mechanisms underlying human diseases. Neurodevelopmental, neurodegenerative, and psychiatric disorders are particularly multifactorial and heterogeneous, making...

Deep brain stimulation (DBS) is effective for treating neurological and psychiatric disorders. However, its tethered configuration, invasiveness, and limited tissue compatibility motivate wireless, minimally invasive alternatives. Here, we develop an in situ-gelled injectable conductive hydrogel (ICH), enabling wireless neuromodulation via electric-field localization under volume conduction. The ICH forms in vivo through bio-catalyzed polymerization and electrostatic self-assembly, yielding a...

Parkinson's disease (PD) is an incurable neurological disorder that often begins insidiously with sleep disturbances and somatic symptoms, progressing to whole-body motor and cognitive symptoms^(1-5). Dysfunction of the somato-cognitive action network (SCAN)-which is thought to control action execution^(6,7) by coordinating arousal, organ physiology and whole-body motor plans with behavioural motivation-is a potential contributor to the diverse clinical manifestations of PD. To investigate the...

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Biofluid-based biomarkers have transformed neurodegenerative disease research and care, providing insights into the molecular underpinnings of Alzheimer's disease (AD) and other neurodegenerative dementias. This Review provides an update on recent developments in biofluid-based biomarkers for amyloid-β (Aβ) pathology, tau pathology, neurodegeneration, glial reactivity, α-synuclein pathology, TAR DNA-binding protein 43 (TDP-43) pathology, synaptic pathophysiology and cerebrovascular...

Genome-wide association studies strongly implicate neuroinflammation in late-onset Alzheimer's disease (LOAD). Genetic risk loci for LOAD are enriched for genes expressed in microglia, but the relationship among microglial LOAD risk genes has been unclear. We found that the N-terminal SH2 domain of INPP5D, an important LOAD risk gene, directly interacted with the cell death regulator RIPK1 at p-Y383 to suppress RIPK1 kinase activation. Microglial INPP5D deficiency cell-autonomously promoted...

Dietary capsaicin intake appears to affect the pathogenesis of Alzheimer's disease (AD), while the underlying mechanisms remain unclear. Here, we found in human cohorts that moderate-to-high level of dietary capsaicin intake was associated with improved cognitive performance. Similarly, long-term oral capsaicin administration in male 5×FAD mice ameliorated AD-like pathologies and reshaped gut microbial composition. Gut microbiota transfer from capsaicin-treated mice produced similar effects of...

Microglial phagocytosis exerts essential roles in neurodegeneration, but how phagocytic processes may reciprocally regulate microglia remains incompletely understood. Here, we report that microglial response in the mouse model of pathological axonal degeneration depends on the phagocytic receptor MerTK. The MerTK-triggered downstream phospholipase C signal is sufficient to induce the up-regulation of PU.1 and IRF8, the two central transcription factors governing microglial functions. Chromatin...

Tyrosine nitration alters the structure, function, and cellular localization of proteins and is implicated in the pathology of multiple diseases [G. Ferrer-Sueta et al., Chem. Rev. 118, 1338-1408 (2018), H. Ischiropoulos, Arch. Biochem. Biophys. 356, 1-11 (1998), I. Griswold-Prenner et al., J. Biol. Chem. 299, 105038-10554 (2023)]. Although protein nitration is assumed to proceed via nonspecific chemical mechanisms, it is highly selective, suggesting the possibility of enzymatic catalysis. Here,...

Amyloid β (Aβ) accumulation is a hallmark of Alzheimer's disease (AD). Emerging evidence suggests that impaired microglial Aβ phagocytosis is a key feature in AD, highlighting the therapeutic potential of enhancing this innate immune function. Here, we demonstrate that genetic deletion or pharmacological inhibition of protein tyrosine phosphatase 1B (PTP1B) ameliorated memory deficits and reduced Aβ burden in APP/PS1 mice. Moreover, we show that PTP1B was highly expressed in microglia, and its...

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The APOE-ε4/ε4 genotype is the strongest genetic risk factor for sporadic Alzheimer's disease, though the relative risk is diminished in individuals with African ancestry. Through analysis of phased APOE alleles, we identify a 19 bp deletion approximately 1.1 kb distal to the APOE 3'UTR in a SPI1 microglial transcription factor binding site. The deletion is present in 60% of African American APOE-ε4 homozygotes and reduces Alzheimer's disease odds ratio relative to individuals without the...

Accurately predicting disease progression remains a major challenge in Alzheimer's disease (AD). Here we show that a biomarker-integrated prognostic staging system can stratify progression risk across the disease course by jointly incorporating cognitive status, established risk factors, plasma biomarkers, and neuroimaging measures. In the K-ROAD cohort (N = 1,263), the dominant prognostic contributors varied by clinical context-GFAP in cognitively unimpaired individuals, hippocampal volume in...

The nasal microbiome has emerged as a previously underrecognized modulator of neuroinflammation and central nervous system (CNS) homeostasis. Beyond its role in respiratory host defense, this microbial niche is anatomically positioned to directly influence brain physiology through olfactory neuronal pathways, systemic immune signaling, and inter-organ communication within the gut-lung-brain axis. Accumulating evidence indicates that nasal microbiome dysbiosis contributes to blood-brain barrier...

Selective neuronal vulnerability is a hallmark of Alzheimer's disease (AD), yet the molecular basis of resilience remains poorly understood. Using single-nucleus and spatial transcriptomics to compare neocortical regions affected early (prefrontal cortex, precuneus) or late (primary visual cortex) in AD, we identified a resilient excitatory population in layer 4 of the primary visual cortex expressing RORB, CUX2, and EYA4. Layer 4 neurons in association neocortex shared molecular signatures of...

In Alzheimer's disease (AD), pathological tau protein shows a progressive accumulation of post-translational modifications (PTMs), reflecting disease severity, progression, and prion-like activity. Although many neurodegenerative diseases with dementia display tau aggregates, the pathological proteoforms of tau protein from each disease type remain unknown. Here, using a quantitative mass spectrometry-based proteomics platform, FLEXITau, deep characterization of pathological tau protein isolated...

Alzheimer's disease (AD) is an age-related progressive neurodegenerative disorder characterized by amyloid-beta (Aβ) plaque deposition, neurofibrillary tangles of hyperphosphorylated tau protein, chronic neuroinflammation, and dysregulation of multiple regulated cell death pathways. Aging, as the primary risk factor for AD, is accompanied by the accumulation of oxidative stress, which serves as a pivotal contributor to AD pathogenesis and is intricately linked to the activation of diverse cell...

Alzheimer's disease (AD) is a neurodegenerative condition characterised by amyloid-β pathology, neuroinflammation, synaptic dysfunction and cognitive decline. Few pharmacological interventions are available, offering only symptomatic relief, and approval for a number of anti-amyloid biologics is limited, with concerns about safety, cost and efficacy. Here we investigated the effects of 8-10 weeks treatment with liraglutide, NAcGIP[Lys(37)PAL] and Xenin-25[Lys(13)PAL], long-lasting analogues of...