introduction: in this study we compared transcranial magnetic stimulation (tms) elicited motor evoked potentials (meps) in a postural (bilateral low back extension: blbe) and a respiratory (forced expiration during breath holding: febh) task.methods: using tms of the left motor cortex, simultaneous patterns of corticospinal facilitation of the contralateral erector spinae (es) and rectus abdomi...

At the onset of dynamic movements excitation of the motor cortex (M1) is spatially restricted to areas representing the involved muscles whereas adjacent areas are inhibited. The current study elucidates whether the cortical motor command for dynamic contractions is also restricted to a certain population of cortical neurons responsible for the fast corticospinal projections. Therefore, cortico...

During early postnatal development, corticospinal (CS) system stimulation, electrical or transcranial magnetic, is minimally effective in producing muscle contraction, despite having axon terminals that excite spinal neurons. Later, after stimulation becomes more effective, the cortical motor representation develops, and movements the system controls in maturity are expressed. We determined whe...

The ventral premotor area (F5) is part of the cortical circuit controlling visuomotor grasp. F5 could influence hand motor function through at least two pathways: corticospinal projections and corticocortical projections to primary motor cortex (M1). We found that stimulation of macaque F5, which by itself evoked little or no detectable corticospinal output, could produce a robust modulation of...

Many different functional roles have been ascribed to the motor system due to its prevalent recruitment in perceptual and cognitive tasks other than motor production. We discuss findings that suggest the motor system might take on multiple roles that vary with context and the brain networks involved. Using single-pulse TMS, we measured the corticospinal excitability of the FDI muscle in primary...

Introduction It is well known that the integrated electromyographic (EMG) activity during lengthening (LEN) contractions is lower than that during shortening (SHO) contractions against the same load (Bigland and Lippold 1954). Even if the EMG activity is at a similar level in both contraction types, the excitability in spinal reflex pathway and/or corticospinal tract is lower during LEN contrac...

Studies using transcranial magnetic stimulation have demonstrated that action observation can modulate the activity of the corticospinal system. This has been attributed to the activity of an 'action observation network', whereby premotor cortex activity influences corticospinal excitability. Neuroimaging studies have demonstrated that the context in which participants observe actions (i.e. whe...

Transmission in the corticospinal and Ia pathways to soleus motoneurons was investigated in healthy human subjects during bicycling. Soleus H reflexes and motor evoked potentials (MEPs) after transcranial magnetic stimulation (TMS) were modulated similarly during the crank cycle being large during downstroke [concomitant with soleus background electromyographic (EMG) activity] and small during ...

The corticospinal pathway is the major pathway controlling human voluntary movements. After strong voluntary contractions, the efficacy of corticospinal transmission to elbow flexors is reduced for approximately 90 s, and this limits motoneuronal output. This reduction may reflect activity-dependent changes at cortico-motoneuronal synapses. We investigated whether similar changes occur in a leg...

Non-physical balance training has demonstrated to be efficient to improve postural control in young people. However, little is known about the potential to increase corticospinal excitability by mental simulation in lower leg muscles. Mental simulation of isolated, voluntary contractions of limb muscles increase corticospinal excitability but more automated tasks like walking seem to have no or...