RT Journal Article
SR Electronic
T1 Age differences in brain white matter microstructure in UK Biobank (N = 3,513)
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 051771
DO 10.1101/051771
A1 Simon R. Cox
A1 Stuart J. Ritchie
A1 Elliot M. Tucker-Drob
A1 David C. Liewald
A1 Saskia P. Hagenaars
A1 Gail Davies
A1 Joanna M. Wardlaw
A1 Catharine R Gale
A1 Mark E. Bastin
A1 Ian J. Deary
YR 2016
UL http://biorxiv.org/content/early/2016/05/04/051771.abstract
AB Quantifying the microstructural properties of the human brain’s connections is necessary for understanding normal ageing and disease states. We examined brain white matter MRI data in 3,513 generally healthy people aged 45-75 years from the UK Biobank sample. Using conventional water diffusion measures and newer, as-yet rarely-studied indices from neurite orientation dispersion and density imaging (NODDI), we document large age differences in white matter microstructure. Mean diffusivity was the most age-sensitive diffusion measure, with negative age associations strongest in the thalamic radiation and association fibres. Inter-individual differences in white matter microstructure across brain tracts become increasingly correlated in older age. This connectivity ‘de-differentiation’ may reflect an age-related aggregation of systemic detrimental effects on the brain. We report several other novel results, including comparative age associations with volumetric indices and associations with hemisphere and sex. Results from this unusually large, single-scanner sample provide one of the most definitive characterisations to date of age differences in major white matter tracts in the human brain.TractsARacoustic radiationATRanterior thalamic radiationCingGcingulum bundle; gyrusCingPHcingulum gyrus; parahippocampalCSTcorticospinal tractFMajforceps majorFMinforceps minorIFOFinferior fronto-occipital fasciculusILFinferior longitudinal fasciculusMCPmiddle cerebellar peduncleMLmedial lemniscusPTRposterior thalamic radiationSLFsuperior longitudinal fasciculusSTRsuperior thalamic radiationUncuncinate fasciculusMeasures of white matter microstructureFAfractional anisotropyICVFintracellular volume fractionISOVFisotropic volume fractionMDmean diffusivityNODDIneurite orientation dispersion and density imagingODorientation dispersion