title: Changes in functional connectivity and GABA levels with long-term motor learning.
abstract: Learning novel motor skills alters local inhibitory circuits within primary motor cortex (M1) (Floyer-Lea et al., 2006) and changes long-range functional connectivity (Albert et al., 2009). Whether such effects occur with long-term training is less well established. In addition, the relationship between learning-related changes in functional connectivity and local inhibition, and their modulation by practice, has not previously been tested. Here, we used resting-state functional magnetic resonance imaging (rs-fMRI) to assess functional connectivity and MR spectroscopy to quantify GABA in primary motor cortex (M1) before and after a 6 week regime of juggling practice. Participants practiced for either 30 min (high intensity group) or 15 min (low intensity group) per day. We hypothesized that different training regimes would be reflected in distinct changes in brain connectivity and local inhibition, and that correlations would be found between learning-induced changes in GABA and functional connectivity. Performance improved significantly with practice in both groups and we found no evidence for differences in performance outcomes between the low intensity and high intensity groups. Despite the absence of behavioral differences, we found distinct patterns of brain change in the two groups: the low intensity group showed increases in functional connectivity in the motor network and decreases in GABA, whereas the high intensity group showed decreases in functional connectivity and no significant change in GABA. Changes in functional connectivity correlated with performance outcome. Learning-related changes in functional connectivity correlated with changes in GABA. The results suggest that different training regimes are associated with distinct patterns of brain change, even when performance outcomes are comparable between practice schedules. Our results further indicate that learning-related changes in resting-state network strength in part reflect GABAergic plastic processes.
authors.affiliation: Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Sampaio-Baptista
authors.affiliation: Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK; Department of Psychiatry, University of Oxford, Warneford Hospital, OX3 7JX, UK.
authors.forename: Nicola
authors.initials: N
authors.lastname: Filippini
authors.affiliation: Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK.
authors.forename: Charlotte J
authors.initials: CJ
authors.lastname: Stagg
authors.affiliation: Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK.
authors.forename: Jamie
authors.initials: J
authors.lastname: Near
authors.affiliation: Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK; Mouse Imaging Centre, Hospital for Sick Children, 25 Orde Street, Toronto, Ontario M5T 3H7, Canada.
authors.forename: Jan
authors.initials: J
authors.lastname: Scholz
authors.affiliation: Oxford Centre for Functional MRI of the Brain (FMRIB), Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK. Electronic address: heidi.johansen-berg@ndcn.ox.ac.uk.
authors.forename: Heidi
authors.initials: H
authors.lastname: Johansen-Berg
mesh_terms: D000222:Adaptation, Physiological / Q000502:physiology; D063132:Connectome / Q000379:methods; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging / Q000379:methods; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009415:Nerve Net / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D009473:Neuronal Plasticity / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D055815:Young Adult; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D018377:Neurotransmitter Agents; D005680:gamma-Aminobutyric Acid
keywords: Functional connectivity; GABA; Motor learning; Plasticity