Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

Ventral premotor cortex (PMv) is widely accepted to exert an important influence over primary motor cortex (M1) when hand movements are made. Although study of these interactions has typically focused on their excitatory nature, given its strong connections with both ventral and opercular frontal regions, one feature of the influence of PMv over M1 may be inhibitory. Paired-pulse transcranial magnetic stimulation (ppTMS) was used to examine functional interactions between human PMv and M1 during the selection and reprogramming of a naturalistic goal-directed action. One of two cylinders was illuminated on each trial. It was then grasped and picked up. On some trials, however, subjects had to reprogram the action as the illuminated cylinder was switched off and the other illuminated simultaneously with reach initiation. At a neurophysiological level, the PMv paired-pulse effect (PPE) on M1 corticospinal activity was facilitatory after the initial target presentation and during movement initiation. When reprogramming was required, however, the PPE became strongly inhibitory. This context-dependent change from facilitation to inhibition occurred within 75 ms of the change of target. Behaviorally, PMv-M1 ppTMS disrupted reprogramming. Diffusion-weighted magnetic resonance image scans were taken of each subject. Intersubject differences in the facilitation-inhibition contrast of PMv-M1 interactions were correlated with fractional anisotropy of white-matter in ventral prefrontal, premotor, and intraparietal brain areas. These results suggest that a network of brain areas centered on PMv inhibits M1 corticospinal activity associated with undesired movements when action plans change.

Original publication

DOI

10.1523/JNEUROSCI.4882-09.2010

Type

Journal article

Journal

J Neurosci

Publication Date

27/01/2010

Volume

30

Pages

1395 - 1401

Keywords

Adult, Brain Mapping, Efferent Pathways, Excitatory Postsynaptic Potentials, Executive Function, Female, Frontal Lobe, Humans, Inhibitory Postsynaptic Potentials, Magnetic Resonance Imaging, Male, Motor Cortex, Movement, Nerve Fibers, Myelinated, Nerve Net, Neural Inhibition, Neuropsychological Tests, Psychomotor Performance, Pyramidal Tracts, Reaction Time, Synaptic Transmission, Time Factors, Transcranial Magnetic Stimulation