title: Distinct temporospatial interhemispheric interactions in the human primary and premotor cortex during movement preparation.
abstract: The preparation of a voluntary unimanual action requires sequential processing in bihemispheric motor areas. In both animals and humans, activity in the dorsal premotor cortex (PMd) ipsilateral to the moving hand has been demonstrated to precede ipsilateral primary motor cortex (M1) activity. We investigated with double-pulse transcranial magnetic stimulation how right-hemispheric motor areas (rM1, rPMd) modulate left M1 (lM1) during the preparatory period of a finger movement with the dominant right hand. We tested the hypothesis that the influence of higher order motor areas such as rPMd on lM1 (rPMd-lM1) precedes interhemispheric interactions between homologue primary motor areas (rM1-lM1). rPMd-lM1 showed modulation in the early and late phase of movement preparation, whereas the intrinsic state of inhibition between rM1-lM1 was only modulated in the late phase. The present results complement existing hierarchical models of cortical movement control by demonstrating temporospatially distinct involvement of interhemispheric interactions from PMd and M1 during movement preparation.
authors.affiliation: Department of Neurology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Gianpiero
authors.initials: G
authors.lastname: Liuzzi
authors.forename: Vanessa
authors.initials: V
authors.lastname: Hörniss
authors.forename: Julia
authors.initials: J
authors.lastname: Hoppe
authors.forename: Kirstin
authors.initials: K
authors.lastname: Heise
authors.forename: Maximo
authors.initials: M
authors.lastname: Zimerman
authors.forename: Christian
authors.initials: C
authors.lastname: Gerloff
authors.forename: Friedhelm C
authors.initials: FC
authors.lastname: Hummel
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods; D004292:Dominance, Cerebral / Q000502:physiology; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D008959:Models, Neurological; D009044:Motor Cortex / Q000033:anatomy & histology* / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D009433:Neural Inhibition / Q000502:physiology; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult