Evidence of association between higher cardiorespiratory fitness and higher cerebral myelination in aging

Proceedings of the National Academy of Sciences, Journal Year: 2024, Volume and Issue: 121(35)

Published: Aug. 19, 2024

Emerging evidence suggests that altered myelination is an important pathophysiologic correlate of several neurodegenerative diseases, including Alzheimer and Parkinson's diseases. Thus, improving myelin integrity may be effective intervention to prevent treat age-associated pathologies. It has been suggested cardiorespiratory fitness (CRF) preserve enhance cerebral throughout the adult lifespan, but this hypothesis not fully tested. Among cognitively normal participants from two well-characterized studies spanning a wide age range, we assessed CRF operationalized as maximum rate oxygen consumption (VO

Language: Английский

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Investigating the association between human brainstem microstructural integrity and hypertension using magnetic resonance relaxometry

Hypertension Research, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 23, 2025

Abstract The brainstem plays a vital role in regulating blood pressure, and disruptions to its neural pathways have been linked hypertension. However, it remains unclear whether subtle microstructural changes the are associated with an individual’s pressure status. This exploratory, cross-sectional study investigated relationship between microstructure, myelination, hypertensive status 116 cognitively unimpaired adults (aged 22–94 years). Advanced MRI techniques, including relaxometry (R1, R2) myelin water fraction (MWF) analysis, were employed assess integrity content ten subregions. Our results revealed significant associations higher damage or lower (indicated by R1, R2, MWF values) status, particularly midbrain tegmentum. Notably, combining these metrics yielded high classification accuracy (AUC > 0.85). findings suggest potential link disrupted tissue integrity, content, elevated warranting further longitudinal investigations explore this relationship.

Language: Английский

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Comparative Sensitivity of MRI Indices for Myelin Assessment in Spinal Cord Regions

Tomography, Journal Year: 2025, Volume and Issue: 11(1), P. 8 - 8

Published: Jan. 14, 2025

Background/Objectives: Although multiple magnetic resonance imaging (MRI) indices are known to be sensitive the noninvasive assessment of myelin integrity, their relative sensitivities have not been directly compared. This study aimed identify most MRI index for characterizing composition in spinal cord’s gray matter (GM) and white (WM). Methods: was performed on a deer’s ex vivo cervical cord. Quantitative myelin, including water fraction (MWF), magnetization transfer ratio (MTR), signal between T1- T2-weighted images (T1W/T2W), fractional anisotropy (FA), mean diffusivity (MD), electrical conductivity (σ), T1, T2, T1ρ relaxation times were calculated. Their values compared using repeated measures analysis variance (ANOVA) post hoc Bonferroni tests or Friedman Wilcoxon differences across GM WM columns possessing distinct distributions, as revealed by histological analysis. Relationships among examined Spearman’s rank-order correlation Corrected p < 0.05 considered statistically significant. Results: All except σ differed significantly all columns. Two three had different MWF, FA, MD, whereas one column MTR, σ, from others. A significant moderate very strong observed indices. Conclusions: The sensitivity distinguishing cord regions varied. strategic combination two more may allow accurate differentiation regions.

Language: Английский

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Age-Related Differences in the Choroid Plexus Structural Integrity Are Associated with Changes in Cognition

medRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 28, 2025

The choroid plexus (CP) plays a critical role in maintaining central nervous system (CNS) homeostasis, producing cerebrospinal fluid, and regulating the entry of specific substances into CNS from blood. CP dysfunction has been implicated various neurological psychiatric disorders, including Alzheimer's disease, Parkinson's multiple sclerosis. This study investigates relationship between structural integrity cognitive decline normative aging, using advanced magnetic resonance imaging techniques, volume, diffusion tensor indices (mean diffusivity, MD, fractional anisotropy, FA) relaxometry metrics (longitudinal, T 1 , transverse, 2 relaxation times). Our results show that diminished microstructural integrity, as reflected by higher MD values, or lower FA is associated with performance processing speed fluency. Notably, measures demonstrated greater sensitivity to than macrostructural measures, i.e. volume. Longitudinal analysis revealed individuals reduced exhibit steeper over time. Furthermore, equation modeling latent variable representing predicts faster overall decline, an effect size comparable age. These findings highlight importance health suggest holistic approach assessing could serve sensitive biomarker for early detection decline. Further research needed elucidate mechanisms underlying explore potential therapeutic implications targeting function prevent treat age-related deficits.

Language: Английский

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Sex and APOE4-specific links between cardiometabolic risk factors and white matter alterations in individuals with a family history of Alzheimer's disease

Neurobiology of Aging, Journal Year: 2025, Volume and Issue: 150, P. 80 - 96

Published: March 8, 2025

Early detection of pathological changes in Alzheimer's disease (AD) has garnered significant attention the last few decades as interventions aiming to prevent progression will likely be most effective when initiated early. White matter (WM) alterations are among earliest AD, yet limited work comprehensively characterized effects AD risk factors on WM. In older adults with a family history we investigated sex-specific and APOE genotype-related relationships between WM microstructure factors. Multiple MRI-derived metrics were integrated using multivariate approach based Mahalanobis distance (D2). To uncover specific biological underpinnings these alterations, then extracted contribution each MRI feature D2 clusters. Lastly, links cognition explored. several regions was associated high systolic blood pressure, BMI, glycated hemoglobin, low cholesterol, both males females. APOE4 + displayed distinct pattern, LDL-cholesterol having detrimental effect only carriers, this pattern linked immediate memory performance. Myelination main mechanism underlying alterations. Our findings reveal that combined exposure multiple cardiometabolic negatively impacts microstructural health, which may subsequently affect cognition. Notably, carriers exhibited different especially role LDL, suggesting mechanisms group.

Language: Английский

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Cerebral white matter myelination is associated with longitudinal changes in processing speed across the adult lifespan

Brain Communications, Journal Year: 2024, Volume and Issue: 6(6)

Published: Jan. 1, 2024

Abstract Myelin’s role in processing speed is pivotal, as it facilitates efficient neural conduction. Its decline could significantly affect cognitive efficiency during ageing. In this work, myelin content was quantified using our advanced MRI method of water fraction mapping. We examined the relationship between at time and retrospective longitudinal change among 121 cognitively unimpaired participants, aged 22–94 years, from Baltimore Longitudinal Study Aging Genetic Epigenetic Signatures Translational Laboratory Testing (a mean follow-up duration 4.3 ± 6.3 years) linear mixed-effects models, adjusting for demographics. found that higher values correlated with longitudinally better-maintained speed, particularly significant associations several white matter regions. Detailed voxel-wise analysis provided further insight into specific tracts involved. This research underscores essential preserving highlights its potential a sensitive biomarker interventions targeting age-related decline, thereby offering foundation preventative strategies neurological health.

Language: Английский

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White matter integrity and motor function: a link between cerebral myelination and longitudinal changes in gait speed in aging

GeroScience, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 30, 2024

Abstract Gait speed is a robust health biomarker in older adults, correlating with the risk of physical and cognitive impairments, including dementia. Myelination plays crucial role neurotransmission consequently affects various functions, yet connection between myelination motor functions such as gait not well understood. Understanding this link could offer insights into diagnosing treating neurodegenerative diseases that impair mobility. This study analyzed 437 longitudinal observations from 138 cognitively unimpaired aged 22 to 94 years, investigate relationship myelin content changes over an average 6.42 years. Myelin was quantified using novel multicomponent magnetic resonance relaxometry method, both usual rapid speeds (UGS, RGS) were measured following standard protocols. Adjusting for covariates, we found significant fixed effect on UGS RGS. Longitudinally, lower linked greater decline UGS, particularly brain regions associated planning. These results suggest may serve reliable marker neurodegeneration, adults. Interestingly, RGS only observed limited number regions, although reason local susceptibility remains unknown. findings enhance our understanding critical performance adults provide evidence interconnection function impairment.

Language: Английский

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Brain microstructure alterations in subjective cognitive decline: a multi-component T2 relaxometry study

Brain Communications, Journal Year: 2024, Volume and Issue: 7(1)

Published: Dec. 24, 2024

Abstract Previous research has revealed patterns of brain atrophy in subjective cognitive decline, a potential preclinical stage Alzheimer’s disease. However, the involvement myelin content and microstructural alterations decline not previously been investigated. This study included three groups participants recruited from Compostela Aging Study project: 53 cognitively unimpaired adults, 16 individuals with hippocampal 70 no atrophy. Group differences were analysed across five MRI biomarkers derived multi-component T2 relaxometry, each sensitive to variations cerebral composition tissue integrity. Although significant observed between groups, group exhibited larger free-water fraction, reduced fraction relaxation times intra/extracellular water compartment frontal, parietal medial temporal lobe regions white matter tracts as compared other groups. Moreover, both displayed lower total control showed without group. These changes are likely related neuroinflammation, axonal degeneration, iron accumulation or physiologic variations, calling for further examinations.

Language: Английский

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