Open AccessChanges in white matter fiber density and morphology across the adult lifespan: A cross‐sectional fixel‐based analysis
Author(s) -
Choy Shao Wei,
Bagarinao Epifanio,
Watanabe Hirohisa,
Ho Eric Tatt Wei,
Maesawa Satoshi,
Mori Daisuke,
Hara Kazuhiro,
Kawabata Kazuya,
Yoneyama Noritaka,
Ohdake Reiko,
Imai Kazunori,
Masuda Michihito,
Yokoi Takamasa,
Ogura Aya,
Taoka Toshiaki,
Koyama Shuji,
Tanabe Hiroki C.,
Katsuno Masahisa,
Wakabayashi Toshihiko,
Kuzuya Masafumi,
Hoshiyama Minoru,
Isoda Haruo,
Naganawa Shinji,
Ozaki Norio,
Sobue Gen
Publication year - 2020
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.25008
Subject(s) - white matter , corpus callosum , cingulum (brain) , anatomy , superior longitudinal fasciculus , fractional anisotropy , fiber tract , psychology , biology , neuroscience , medicine , magnetic resonance imaging , radiology
White matter (WM) fiber bundles change dynamically with age. These changes could be driven by alterations in axonal diameter, axonal density, and myelin content. In this study, we applied a novel fixel‐based analysis (FBA) framework to examine these changes throughout the adult lifespan. Using diffusion‐weighted images from a cohort of 293 healthy volunteers (89 males/204 females) from ages 21 to 86 years old, we performed FBA to analyze age‐related changes in microscopic fiber density (FD) and macroscopic fiber morphology (fiber cross section [FC]). Our results showed significant and widespread age‐related alterations in FD and FC across the whole brain. Interestingly, some fiber bundles such as the anterior thalamic radiation, corpus callosum, and superior longitudinal fasciculus only showed significant negative relationship with age in FD values, but not in FC. On the other hand, some segments of the cerebello‐thalamo‐cortical pathway only showed significant negative relationship with age in FC, but not in FD. Analysis at the tract‐level also showed that major fiber tract groups predominantly distributed in the frontal lobe (cingulum, forceps minor) exhibited greater vulnerability to the aging process than the others. Differences in FC and the combined measure of FD and cross section values observed between sexes were mostly driven by differences in brain sizes although male participants tended to exhibit steeper negative linear relationship with age in FD as compared to female participants. Overall, these findings provide further insights into the structural changes the brain's WM undergoes due to the aging process.