ArticleHuman brain mapping2021
Age-related estimates of aggregate g-ratio of white matter structures assessed using quantitative magnetic resonance neuroimaging.
Article in Human brain mapping, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 25 papers.
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Who cites it
25 citing papers in PubMed, 39 citations in OpenAlex.
- Contributions of Gray Matter Microstructure to Differences in Fluid Cognition and Episodic Memory Across the Healthy Adult Lifespan.Human brain mapping · 2026Article
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- Sub-Networks of the Brain RHuman brain mapping · 2026Article
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- Diffusion MRI Microstructure Markers of Changes in the Human Brain Across the Lifespan Using Constrained Spherical Deconvolution and Fixel-Based Techniques.Human brain mapping · 2025Article
- Association between cardiorespiratory fitness and total brain myelin volume among older adults.European review of aging and physical activity : official journal of the European Group for Research into Elderly and Physical Activity · 2025Article
- Spatial transcriptomics of the aging mouse brain reveals origins of inflammation in the white matter.Nature communications · 2025Article
- Decoding Brain Development and Aging: Pioneering Insights From MRI Techniques.Investigative radiology · 2025Review
- Combined use of olfactory mucosal mesenchymal stem cells conditioned medium and neural guide conduits promotes nerve regeneration in an ovine model.Frontiers in cell and developmental biology · 2025Article
- Interplay between MRI-based axon diameter and myelination estimates in macaque and human brain.Imaging neuroscience (Cambridge, Mass.) · 2025Article
- A tissue bandage for pelvic ganglia injury.Nature communications · 2024Article
- Harnessing myelin water fraction as an imaging biomarker of human cerebral aging, neurodegenerative diseases, and risk factors influencing myelination: A review.Journal of neurochemistry · 2024Review
- Conduction velocity, G-ratio, and extracellular water as microstructural characteristics of autism spectrum disorder.PloS one · 2024Article
- REUSED: A deep neural network method for rapid whole-brain high-resolution myelin water fraction mapping from extremely under-sampled MRI.Computerized medical imaging and graphics : the official journal of the Computerized Medical Imaging Society · 2023Article
- Pathological ultrastructural alterations of myelinated axons in normal appearing white matter in progressive multiple sclerosis.Acta neuropathologica communications · 2023Article
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- C-NODDI: a constrained NODDI model for axonal density and orientation determinations in cerebral white matter.Frontiers in neurology · 2023Article
- Physical activity and the brain myelin content in humans.Frontiers in cellular neuroscience · 2023Review
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- Association of Cerebral Blood Flow With Longitudinal Changes in Cerebral Microstructural Integrity in the Coronary Artery Risk Development in Young Adults (CARDIA) Study.JAMA network open · 2022Article
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Authors and funding
10 authors at 1 institution in 1 country.
Funding
Abstract
The g-ratio, defined as the inner-to-outer diameter of a myelinated axon, is associated with the speed of nerve impulse conduction, and represents an index of axonal myelination and integrity. It has been shown to be a sensitive and specific biomarker of neurodevelopment and neurodegeneration. However, there have been very few magnetic resonance imaging studies of the g-ratio in the context of normative aging; characterizing regional and time-dependent cerebral changes in g-ratio in cognitively normal subjects will be a crucial step in differentiating normal from abnormal microstructural alterations. In the current study, we investigated age-related differences in aggregate g-ratio, that is, g-ratio averaged over all fibers within regions of interest, in several white matter regions in a cohort of 52 cognitively unimpaired participants ranging in age from 21 to 84 years. We found a quadratic, U-shaped, relationship between aggregate g-ratio and age in most cerebral regions investigated, suggesting myelin maturation until middle age followed by a decrease at older ages. As expected, we observed that these age-related differences vary across different brain regions, with the frontal lobes and parietal lobes exhibiting slightly earlier ages of minimum aggregate g-ratio as compared to more posterior structures such as the occipital lobes and temporal lobes; this agrees with the retrogenesis paradigm. Our results provide evidence for a nonlinear association between age and aggregate g-ratio in a sample of adults from a highly controlled population. Finally, sex differences in aggregate g-ratio were observed in several cerebral regions, with women exhibiting overall lower values as compared to men; this likely reflects the greater myelin content in women's brain, in agreement with recent investigations.
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