Detection of motor-learning related neuroplasticity in white matter using functional MRI techniques

Neuroplastic change has been investigated extensively in the brain's grey matter, focusing largely on activity dependent modulation of synapses. However, new work has supported the presence of neuroplastic change in white matter through modulation of myelination, or other mechanisms. Though structural neuroimaging studies have detected neuroplastic change in white matter, we currently lack MRI based methods of tracking functional changes in the white matter in vivo. To address this gap in the literature, we investigated the patterns of BOLD fMRI activation in white matter. Participants completed two weeks of motor training, using both their dominant and non-dominant hand, in order to stimulate neuroplastic change, and fMRI activity was compared between timepoints, revealing white matter activation in the group level at each timepoint. No difference in amplitude of activation was detected at the group level, but a change in the temporal characteristics of the hemodynamic response was noted in the pre/post training contrast for the non-dominant hand.