title: Working memory training impacts the mean diffusivity in the dopaminergic system.
abstract: Dopaminergic transmission plays a critical role in working memory (WM). Mean diffusivity (MD) is a sensitive and unique neuroimaging tool for detecting microstructural differences particularly in the areas of the dopaminergic system. Despite previous investigation of the effects of WM training (WMT) on dopamine receptor binding potentials, the effects of WMT on MD remain unknown. In this study, we investigated these effects in young adult subjects who either underwent WMT or received no intervention for 4 weeks. Before and after the intervention or no-intervention periods, subjects underwent scanning sessions in diffusion-weighted imaging to measure MD. Compared with no intervention, WMT resulted in an increase in MD in the bilateral caudate, right putamen, left dorsolateral prefrontal cortex (DLPFC), right anterior cingulate cortex (ACC), right substantia nigra, and ventral tegmental area. Furthermore, the increase in performance on WMT tasks was significantly positively correlated with the mean increase in MD in the clusters of the left DLPFC and of the right ACC. These results suggest that WMT caused microstructural changes in the regions of the dopaminergic system in a way that is usually interpreted as a reduction in neural components.
authors.affiliation: Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai, 980-8575, Japan. takehi@idac.tohoku.ac.jp.
authors.forename: Hikaru
authors.initials: H
authors.lastname: Takeuchi
authors.affiliation: Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai, 980-8575, Japan.|Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan.|Department of Radiology and Nuclear Medicine, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Taki
authors.affiliation: Human and Social Response Research Division, International Research Institute of Disaster Science, Tohoku University, Sendai, Japan.
authors.forename: Rui
authors.initials: R
authors.lastname: Nouchi
authors.affiliation: Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hashizume
authors.affiliation: Division of Medical Neuroimaging Analysis, Department of Community Medical Supports, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan.|Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sekiguchi
authors.affiliation: Smart Ageing International Research Center, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Kotozaki
authors.affiliation: Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Seishu
authors.initials: S
authors.lastname: Nakagawa
authors.affiliation: Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.|Graduate School of Arts and Sciences, The University of Tokyo, Tokyo, Japan.
authors.forename: Carlos Makoto
authors.initials: CM
authors.lastname: Miyauchi
authors.affiliation: Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai, 980-8575, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Sassa
authors.affiliation: Division of Developmental Cognitive Neuroscience, Institute of Development, Aging and Cancer, Tohoku University, 4-1 Seiryo-cho, Aoba-ku, Sendai, 980-8575, Japan.|Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.|Smart Ageing International Research Center, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan.
authors.forename: Ryuta
authors.initials: R
authors.lastname: Kawashima
mesh_terms: D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D004298:Dopamine / Q000502:physiology*; D059290:Dopaminergic Neurons / Q000502:physiology*; D005260:Female; D006179:Gyrus Cinguli / Q000502:physiology; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D059906:Neuroimaging / Q000379:methods; D009473:Neuronal Plasticity / Q000502:physiology; D009483:Neuropsychological Tests; D017397:Prefrontal Cortex / Q000502:physiology; D055815:Young Adult
chemical_list: D004298:Dopamine
keywords: Diffusion-weighted imaging; Dopamine; MRI; Mean diffusivity; Plasticity; Training; Working memory