White matter and neurochemical mechanisms underlying age-related differences in motor processing speed
Amirhossein Rasooli,
Hamed Zivari Adab,
Peter Van Ruitenbeek,
Akila Weerasekera,
Sima Chalavi,
Koen Cuypers,
Oron Levin,
Thijs Dhollander,
Ronald Peeters,
Stefan Sunaert,
Dante Mantini,
Stephan P. Swinnen
Affiliations
Amirhossein Rasooli
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
Hamed Zivari Adab
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
Peter Van Ruitenbeek
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, 6200 MD Maastricht, the Netherlands
Akila Weerasekera
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium; Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
Sima Chalavi
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
Koen Cuypers
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium; REVAL Rehabilitation Research Center, Hasselt University, Diepenbeek, Belgium
Oron Levin
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
Thijs Dhollander
Murdoch Children’s Research Institute, Melbourne, VIC, Australia
Ronald Peeters
KU Leuven, Department of Imaging and Pathology, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
Stefan Sunaert
KU Leuven, Department of Imaging and Pathology, Group Biomedical Sciences, KU Leuven, Leuven, Belgium
Dante Mantini
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium
Stephan P. Swinnen
Movement Control & Neuroplasticity Research Group, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; KU Leuven Brain Institute, KU Leuven, Leuven, Belgium; Corresponding author
Summary: Aging is associated with changes in the central nervous system and leads to reduced life quality. Here, we investigated the age-related differences in the CNS underlying motor performance deficits using magnetic resonance spectroscopy and diffusion MRI. MRS measured N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr) concentrations in the sensorimotor and occipital cortex, whereas dMRI quantified apparent fiber density (FD) in the same voxels to evaluate white matter microstructural organization. We found that aging was associated with increased reaction time and reduced FD and NAA concentration in the sensorimotor voxel. Both FD and NAA mediated the association between age and reaction time. The NAA concentration was found to mediate the association between age and FD in the sensorimotor voxel. We propose that the age-related decrease in NAA concentration may result in reduced axonal fiber density in the sensorimotor cortex which may ultimately account for the response slowness of older participants.
