title: Contribution of the premotor cortex to consolidation of motor sequence learning in humans during sleep.
abstract: Motor learning and memory consolidation require the contribution of different cortices. For motor sequence learning, the primary motor cortex is involved primarily in its acquisition. Premotor areas might be important for consolidation. In accordance, modulation of cortical excitability via transcranial DC stimulation (tDCS) during learning affects performance when applied to the primary motor cortex, but not premotor cortex. We aimed to explore whether premotor tDCS influences task performance during motor memory consolidation. The impact of excitability-enhancing, -diminishing, or placebo premotor tDCS during rapid eye movement (REM) sleep on recall in the serial reaction time task (SRTT) was explored in healthy humans. The motor task was learned in the evening. Recall was performed immediately after tDCS or the following morning. In two separate control experiments, excitability-enhancing premotor tDCS was performed 4 h after task learning during daytime or immediately before conduction of a simple reaction time task. Excitability-enhancing tDCS performed during REM sleep increased recall of the learned movement sequences, when tested immediately after stimulation. REM density was enhanced by excitability-increasing tDCS and reduced by inhibitory tDCS, but did not correlate with task performance. In the control experiments, tDCS did not improve performance. We conclude that the premotor cortex is involved in motor memory consolidation during REM sleep.
authors.affiliation: Georg-August-University, Department of Clinical Neurophysiology, Göttingen, Germany. mnitsch1@gwdg.de
authors.forename: Michael A
authors.initials: MA
authors.lastname: Nitsche
authors.forename: Michaela
authors.initials: M
authors.lastname: Jakoubkova
authors.forename: Nivethida
authors.initials: N
authors.lastname: Thirugnanasambandam
authors.forename: Leonie
authors.initials: L
authors.lastname: Schmalfuss
authors.forename: Sandra
authors.initials: S
authors.lastname: Hullemann
authors.forename: Karel
authors.initials: K
authors.lastname: Sonka
authors.forename: Walter
authors.initials: W
authors.lastname: Paulus
authors.forename: Claudia
authors.initials: C
authors.lastname: Trenkwalder
authors.forename: Svenja
authors.initials: S
authors.lastname: Happe
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004558:Electric Stimulation; D004576:Electromyography; D005260:Female; D006801:Humans; D007858:Learning / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology*; D017286:Polysomnography; D011930:Reaction Time / Q000502:physiology; D012890:Sleep / Q000502:physiology*