Short latency inhibition of human hand motor cortex by somatosensory input from the hand

By H. Tokimura, V. Lazzaro, Y. Tokimura, A. Oliviero, P. Profice, A. Insola, P. Mazzone, P. Tonali, John C. Rothwell. Journal of Physiology, 2000

751 citations recorded by the source corpus.

1 EMG responses evoked in hand muscles by transcranial stimulation over the motor cortex were conditioned by a single motor threshold electrical stimulus to the median nerve at the wrist in a total of ten healthy subjects and in five patients who had electrodes implanted chronically into the cervical epidural space. 2 The median nerve stimulus suppressed responses evoked by transcranial magnetic stimulation (TMS) in relaxed or active muscle. The minimum interval between the stimuli at which this occurred was 19 ms. A similar effect was seen if electrical stimulation was applied to the digital nerves of the first two fingers. 3 Median or digital nerve stimulation could suppress the responses evoked in active muscle by transcranial electrical stimulation over the motor cortex, but the effect was much less than with magnetic stimulation. 4 During contraction without TMS, both types of conditioning stimuli evoked a cutaneomuscular reflex that began with a short period of inhibition. This started about 5 ms after the inhibition of responses evoked by TMS. 5 Recordings in the patients showed that median nerve stimulation reduced the size and number of descending corticospinal volleys evoked by magnetic stimulation. 6 We conclude that mixed or cutaneous input from the hand can suppress the excitability of the motor cortex at short latency. This suppression may contribute to the initial inhibition of the cutaneomuscular reflex. Reduced spinal excitability in this period could account for the mild inhibition of responses to electrical brain stimulation.

Subfields: Cognitive Neuroscience, Neurology

View Paper: https://www.semanticscholar.org/paper/994d81369f3abffc0a3713af7ac95fd4cece8ac2

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Citations in the corpus

TMS and drugs revisited 2014. (2015, methodology): “SAI refers to a MEP inhibition in a hand muscle produced by a conditioning afferent electrical stimulus applied to the median or ulnar nerve at the wrist approximately 20 ms prior to focal TMS of the hand area of the contralateral motor cortex (Tokimura et al., 2000).”
The Hierarchical Organisation of Cortical and Basal-Ganglia Systems: A Computationally-Informed Review and Integrated Hypothesis (2013, positive): “, somatosensory cortex encoding the current state of the musculoskeletal system) to primary motor cortex (encoding motor commands to muscles) (Pavlides et al., 1993; Tokimura et al., 2000).”
Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee (2015, background): “Cutaneous or mixed afferent input from the hand can inhibit MEPs evoked in resting muscles by TMS of the motor cortex at remarkably short latencies with a reduction of cortical excitability which has been confirmed also by epidural spinal cord recordings (Tokimura et al., 2000).”
The physiological basis of transcranial motor cortex stimulation in conscious humans. (2004, background): “7) (Tokimura et al., 2000).”
Mechanisms of enhancement of human motor cortex excitability induced by interventional paired associative stimulation (2002, methodology): “The TMS-evoked MEP may be attenuated by stimulation of a contralateral afferent nerve (Tokimura et al. 2000).”
TMS and drugs. (2004, background): “Short latency afferent inhibition (SAI) is defined as an MEP inhibition produced by a conditioning afferent pulse applied to the median nerve at the wrist approximately 20 ms prior to TMS of the hand area of the contralateral motor cortex (Tokimura, 2000).”