Early stages of sensorimotor map acquisition: neurochemical signature in primary motor cortex and its relation to functional connectivity.

TitleEarly stages of sensorimotor map acquisition: neurochemical signature in primary motor cortex and its relation to functional connectivity.
Publication TypeJournal Article
Year of Publication2020
Authorsvan Vugt FT, Near J, Hennessy TJ, Doyon J, Ostry DJ
JournalJ Neurophysiol
Date Published2020 Sep 30
ISSN1522-1598
Abstract

The earliest stages of sensorimotor learning involve learning the correspondence between movements and sensory results: a sensorimotor map. The present exploratory study investigated the neurochemical underpinnings of sensorimotor map acquisition by monitoring twenty-five participants as they acquired a new association between movements and sounds. Functional magnetic resonance spectroscopy (fMRS) was used to measure neurochemical concentrations in left primary motor cortex during learning. Resting state functional magnetic resonance imaging (rsfMRI) was also collected before and after training to assess learning-related changes in functional connectivity. There were monotonic increases in γ-aminobutyric acid (GABA) and decreases in glucose during training, which extended into the subsequent rest period and, importantly, in the case of GABA correlated with the amount of learning: participants who showed greater behavioral learning showed greater GABA increase. The GABA change was furthermore correlated with changes in functional connectivity between primary motor cortex and a cluster of voxels in the right intraparietal sulcus (IPS): greater increases in GABA were associated with greater strengthening of connectivity. Transiently, there were increases in lactate and reductions in aspartate, which returned to baseline at the end of training but only lactate showed a statistical trend to correlate with the amount of learning. In sum, during the earliest stages of sensorimotor learning, GABA levels are linked on a subject level basis to both behavioral learning and to a strengthening of functional connections that persists beyond the training period. The findings are consistent with the idea that GABA-mediated inhibition is linked to maintenance of newly learned information.

DOI10.1152/jn.00285.2020
Alternate JournalJ Neurophysiol
PubMed ID32997558
Grant ListHD075740 / / HHS | NIH | National Institute of Child Health and Human Development (NICHD) /
/ / Fonds Québécois de la Recherche sur la Nature et les Technologies (FQRNT) /
BPF-NSERC-01098 / / Vanier Banting Fellowship /
382252 / / Gouvernement du Canada | CIHR | Institute of Health Services and Policy Research (IHSPR) /