Effects of repetitive cortical stimulation on the silent period evoked by magnetic stimulation
Experimental Brain ResearchPublished 18 February 1999
Alfredo Berardelli, Maurizio Inghilleri, F. Gilio, Stefano Romeo, F. Pedace, Antonio Currà
Citations90
SJR quartileQ3
SJR score0.64
SNIP0.80
Generate an AI Snapshot to get a quick, structured summary of this paper.
Study Snapshot
ObjectiveStudy objective
MethodsResearch methodology
PopulationPopulation studied
Sample sizeSample sizes
OutcomesStudy outcomes here
ResultsStudy results comes here
LimitationsResearch study limitations comes here
A concise AI-generated summary of the paper will appear here once you click Generate AI Snapshot.
TL;DR
Findings show that rTMS increases the duration of the cortical SP, but does so only during the train of stimuli, probably changes the duration by facilitating cortical inhibitory interneurons.
Abstract
The effects of repetitive transcranial stimulation (rTMS) on brain activity remain unknown. In healthy subjects, we studied the effects of rTMS on the duration of the cortical silent period (SP). Repetitive stimuli were delivered with a Cadwell High Speed Magnetic Stimulator and a figure-of-eight coil placed over the hand motor area. rTMS was delivered in trains of 11 or 20 stimuli at frequencies of 3 and 5 Hz and at stimulation intensities of 110 and 120% of motor threshold. The SP was recorded from the forearm muscles during a voluntary contraction (20% of maximum effort). rTMS delivered at a frequency of 3 and 5 Hz and intensities of 110 and 120% motor threshold prolonged the duration of the SP, without modifying either the size or the latency of the muscle-evoked potentials (MEP). A conditioning train of 11 stimuli at 3 Hz had no effect on the duration of the SP evoked by a single magnetic shock delivered 600 ms after the train. These findings show that rTMS increases the duration of the cortical SP, but does so only during the train of stimuli. rTMS probably changes the duration of the SP by facilitating cortical inhibitory interneurons.
Keywords
Neuroscience
NeurologyDepression of motor cortex excitability by low‐frequency transcranial magnetic stimulation
2,136 Citations1997R. Chen, Joseph Claßen +5 more
Spread of excitation, which may be a warning sign for seizures, occurred in one subject and was not accompanied by increased MEP amplitude, suggesting that spread ofexcitation and amplitude changes are different phenomena and also indicating the need for adequate monitoring even with stimulations at low frequencies.
Proceedings of the National Academy of SciencesHomosynaptic long-term depression in area CA1 of hippocampus and effects of N-methyl-D-aspartate receptor blockade.
1,692 Citations1992Serena M. Dudek, Mark F. Bear
The data suggest that synaptic depression can be triggered by prolonged NMDA receptor activation that is below the threshold for inducing synaptic potentiation, and it is proposed that this mechanism is important for the modifications of hippocampal response properties that underlie some forms of learning and memory.
BrainResponses to rapid-rate transcranial magnetic stimulation of the human motor cortex
1,457 Citations1994Álvaro Pascual‐Leone, Josep Valls‐Solé +2 more
Modulation of the amplitude of motor evoked potentials (MEPs) produced in the target muscle during rTMS showed a pattern of inhibitory and excitatory effects which depended on the rT MS frequency and intensity, which suggests that the spread might be due to the breakdown of inhibitORY connections or the recruitment of excited pathways, whereas the post-stimulation facilitation may beDue to a transient increase in the efficacy of excitatories.
NeuronMechanisms underlying induction of homosynaptic long-term depression in area CA1 of the hippocampus
1,101 Citations1992Rosel M. Mulkey, Robert C. Malenka
Induction of homosynaptic LTD requires an NMDA receptor-dependent change in postsynaptic Ca2+ which may be distinct from that required for long-term potentiation.
The Journal of PhysiologySilent period evoked by transcranial stimulation of the human cortex and cervicomedullary junction.
775 Citations1993Maurizio Inghilleri, Alfredo Berardelli +2 more
The findings indicate that the first 50 ms of the silent period after TCS are produced mainly by spinal mechanisms such as after‐hyperpolarization and recurrent inhibition of the spinal motoneurones and if descending inhibitory fibres contribute, their contribution is small.
Electroencephalography and Clinical Neurophysiology/Evoked Potentials SectionSpinal motor neuron excitability during the silent period after cortical stimulation
606 Citations1991Peter Fuhr, Rocco Agostino +1 more
The findings imply, at least in the late part of the silent period, that a reduction in the excitability of the spinal motor neuron pool plays only a minor role in determining the phenomenon and that it is probably caused by lack of cortical drive.
Experimental Brain ResearchFacilitation of muscle evoked responses after repetitive cortical stimulation in man
405 Citations1998Alfredo Berardelli, Maurizio Inghilleri +6 more
RTMS of these parameters increases the excitability of the motor cortex and that this effect outlasts the train for almost 1 s, and at the spinal level, rTMS may increase presynaptic inhibition of Ia afferent fibers responsible for the H-reflex.
Trends in NeurosciencesPhysiological mechanisms underlying long-term potentiation
403 Citations1988Bengt Gustafsson, Holger Wigström
Recent work on long-term potentiation (LTP) is reviewed, a form of synaptic plasticity that has been considered a prime candidate for information storage in the mammalian brain and the induction of which has been surmised to depend on simultaneous pre- and post-synaptic activity.
The Journal of PhysiologyChanges in motor cortical excitability during human muscle fatigue.
366 Citations1996Janet L. Taylor, Jane E. Butler +2 more
The altered EMG responses to transcranial stimulation during fatigue suggest exitation and increased inhibition in the motor cortex, as these changes were un manipulation of afferent input they presumably result from intrinsic cortical pr altered voluntary drive to the Motor cortex.
BrainMotor cortical inhibition and the dopaminergic system
340 Citations1994Alberto Priori, Alfredo Berardelli +3 more
Dopaminergic drugs modulate the duration of the cortical silent periods in patients and in normal subjects, through mechanisms acting mainly at basal ganglia and possibly also directly at cortical level.
The Journal of PhysiologyLong‐term synaptic enhancement and short‐term potentiation in rat fascia dentata act through different mechanisms
331 Citations1982Bruce L. McNaughton
The component processes contributing to post‐activation change in synaptic efficacy in the perforant pathway to the fascia dentata were studied in rats under sodium pentobarbitone anaesthesia.
Experimental Brain ResearchOn the origin of the postexcitatory inhibition seen after transcranial magnetic brain stimulation in awake human subjects
300 Citations1993H. Roick, H.‐J. von Giesen +1 more
The findings imply that spinal segmental inhibitory action cannot account for PI and that inhibitory actions within the motor cortex play a major role in the genesis of PI.
NeurologyAkinesia in Parkinson's disease. II. Effects of subthreshold repetitive transcranial motor cortex stimulation
269 Citations1994Álvaro Pascual‐Leone, Josep Valls‐Solé +4 more
Repetitive, subthreshold motor cortex stimulation can improve performance in patients with PD and could be useful therapeutically.
NeurologyAbnormal cortical motor excitability in dystonia
241 Citations1996Katsunori Ikoma, Ali Samii +3 more
Cortical motor excitability is increased in dystonia, and transcranial magnetic stimuli delivered at different stimulus intensities and with different levels of muscle facilitation recorded motor evoked potentials from the flexor carpi radialis muscles bilaterally.
BrainThe motor syndrome associated with exaggerated inhibition within the primary motor cortex of patients with hemiparetic
221 Citations1997Joseph Claßen
It is suggested that in stroke patients severe motor dysfunction may be caused by hyperactivity of cortical inhibitory interneurons rather than by direct lesions of descending motor tracts.
Experimental Brain ResearchEffects of diazepam, baclofen and thiopental on the silent period evoked by transcranial magnetic stimulation in humans
219 Citations1996Maurizio Inghilleri, Alfredo Berardelli +2 more
Findings show that the cortical silent period can be modified pharmacologically, and Diazepam possibly shortens the silent period by modulating GABA A receptors at a subcortical site.
ScienceAssociative Induction of Posttetanic and Long-Term Potentiation in CA1 Neurons of Rat Hippocampus
217 Citations1986B.R. Sastry, J. W. Goh +1 more
Electrical stimulation of fibers in the stratum radiatum causes an excitatory postsynaptic potential in CA1 neurons of the hippocampus, and this enhancement was characterized as a brief potentiation and a long-term potentiation (presumed to be involved in learning and memory).
European Journal of NeuroscienceLong‐term Depression of Horizontal Connections in Rat Motor Cortex
166 Citations1996Grzegorz Hess, John P. Donoghue
The data demonstrate that activity‐dependent mechanisms may regulate bidirectionally the effectiveness of horizontal synaptic coupling between cortical neurons, thus forming a potential mechanism for plasticity of cortical connections and the representation patterns they support.
Movement DisordersAlterations of motor cortical inhibition in patients with dystonia
162 Citations1998Sabine Rona, Alfredo Berardelli +3 more
It is proposed that the alterations observed in patients with dystonia are the result of impaired feedback from the basal ganglia to motor cortical areas, with the ultimate effect of a flattening of the excitability curve of the cortical motoneuron pool during voluntary muscle activation.
The Journal of PhysiologyEffect of tonic voluntary activity on the excitability of human motor cortex.
139 Citations1994Riccardo Mazzocchio, John C. Rothwell +2 more
It is concluded that tonic voluntary contraction of a target muscle decreases the threshold for indirect activation of corticospinal neurones but not for direct stimulation of their axons.
Movement DisordersElectromyographic silent period after transcranial brain stimulation in huntington's disease
76 Citations1994Alberto Priori, Alfredo Berardelli +3 more
The prolongation of the cortical silent period suggests that the duration of the silent period is a functional correlate reflecting basal ganglia influence over the motor cortex.
NeurologyImpairment of masticatory function in hemiplegia
42 Citations1988G. Cruccu, M. Fornarelli +1 more
Though the masticatory nucleus receives bilateral innervation, the contralateral hemisphere exerts a predominant control on voluntary activity and multisynaptic reflexes in masseter muscle function in hemiplegic patients.
Electroencephalography and Clinical Neurophysiology/Electromyography and Motor ControlThe effect of hyperventilation on motor cortical inhibition in humans: a study of the electromyographic silent period evoked by transcranial brain stimulation
32 Citations1995Alberto Priori, Alfredo Berardelli +3 more
It is suggested that hyperventilation selectively depresses motor cortical inhibition in humans throughhyperventilation under control of the end-tidal PCO2.
Brain ResearchHeterosynaptic short-term depression of population spike amplitude in the pyramidal layer of the CA1 hippocampal region evoked by a theta-like tetanization
7 Citations1993Alexander M. Kleschevnikov, R. M. Marchbanks
Data show that theta-like tetanization is an effective pattern not only for induction of the long-term potentiation (LTP), as has been shown previously, but for production of the heterosynaptic STD as well.