- •For tSMS, NdFeB magnet was settled over the sensorimotor cortex.
- •Amplitudes of the SEP at C3' significantly decreased after tSMS by up to 20%.
- •tSMS might be a useful tool for inducing plasticity in somatosensory processing.
The motor cortex in the human brain can be modulated by the application of transcranial static magnetic field stimulation (tSMS) through the scalp. However, the effect of tSMS on the excitability of the primary somatosensory cortex (S1) in humans has never been examined.
This study was performed to investigate the possibility of non-invasive modulation of S1 excitability by the application of tSMS in healthy humans.
tSMS and sham stimulation over the sensorimotor cortex were applied to 10 subjects for periods of 10 and 15 min. Somatosensory evoked potentials (SEPs) following right median nerve stimulation were recorded before and immediately after, 5 min after, and 10 min after tSMS from sites C3′ and F3 of the international 10-20 system of electrode placement. In another session, SEPs were recorded from 6 of the 10 subjects every 3 min during 15 min of tSMS.
Amplitudes of the N20 component of SEPs at C3′ significantly decreased immediately after 10 and 15 min of tSMS by up to 20%, returning to baseline by 10 min after intervention. tSMS applied while recording SEPs every 3 min and sham stimulation had no effect on SEP.
tSMS is able to modulate cortical somatosensory processing in humans, and thus might be a useful tool for inducing plasticity in cortical somatosensory processing. Lack of change in the amplitude of SEPs with tSMS implies that use of peripheral nerve stimulation to cause SEPs antagonizes alteration of the function of membrane ion channels during exposure to static magnetic fields.
Abbreviations:MEP (motor evoked potential), NdFeB (neodymium, iron, and boron), QPS (quadripulse stimulation), rTMS (repetitive transcranial magnetic stimulation), S1 (primary somatosensory cortex), SEP (somatosensory evoked potential), SMF (static magnetic field), TBS (theta-burst stimulation), tDCS (transcranial direct current stimulation), TMS (transcranial magnetic stimulation), tSMS (transcranial static magnetic field stimulation)
To read this article in full you will need to make a payment
Purchase one-time access:Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
One-time access price info
- For academic or personal research use, select 'Academic and Personal'
- For corporate R&D use, select 'Corporate R&D Professionals'
Subscribe:Subscribe to Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation
Already a print subscriber? Claim online access
Already an online subscriber? Sign in
Register: Create an account
Institutional Access: Sign in to ScienceDirect
- Electric and magnetic stimulation of human motor cortex: surface EMG and single motor unit responses.J Physiol. 1989; 412: 449-473
- Theta burst stimulation of the human motor cortex.Neuron. 2005; 45: 201-206
- Quadro-pulse stimulation is more effective than paired-pulse stimulation for plasticity induction of the human motor cortex.Clin Neurophysiol. 2007; 118: 2672-2682
- Excitability changes induced in the human motor cortex by weak transcranial direct current stimulation.J Physiol. 2000; 527 Pt 3: 633-639
- Transcranial static magnetic field stimulation of the human motor cortex.J Physiol. 2011; 589: 4949-4958
- Inverse correlation between resting motor threshold and corticomotor excitability after static magnetic stimulation of human motor cortex.Brain Stimul. 2013; 6: 817-820
- Effect of a 0.5-T static magnetic field on conduction in guinea pig spinal cord.J Neurol Sci. 2004; 222: 55-57
- Membrane response to static magnetic fields: effect of exposure duration.Biochim Biophys Acta. 1993; 1148: 317-320
- Effects of repetitive transcranial magnetic stimulation on somatosensory evoked potentials and high frequency oscillations in migraine.Cephalalgia. 2012; 32: 700-709
- Decreased sensory cortical excitability after 1 Hz rTMS over the ipsilateral primary motor cortex.Clin Neurophysiol. 2001; 112: 2154-2158
- Long lasting effects of rTMS and associated peripheral sensory input on MEPs, SEPs and transcortical reflex excitability in humans.J Physiol. 2002; 540: 367-376
- Effect of theta burst stimulation over the human sensorimotor cortex on motor and somatosensory evoked potentials.Clin Neurophysiol. 2007; 118: 1033-1043
- Theta-burst stimulation-induced plasticity over primary somatosensory cortex changes somatosensory temporal discrimination in healthy humans.PLoS One. 2012; 7: e32979
- On-line effects of quadripulse transcranial magnetic stimulation (QPS) on the contralateral hemisphere studied with somatosensory evoked potentials and near infrared spectroscopy.Exp Brain Res. 2011; 214: 577-586
- Bidirectional modulation of sensory cortical excitability by quadripulse transcranial magnetic stimulation (QPS) in humans.Clin Neurophysiol. 2012; 123: 1415-1421
- Transcranial direct current stimulation applied over the somatosensory cortex – differential effect on low and high frequency SEPs.Clin Neurophysiol. 2006; 117: 2221-2227
- Transcranial direct current stimulation over the motor association cortex induces plastic changes in ipsilateral primary motor and somatosensory cortices.Clin Neurophysiol. 2011; 122: 777-783
- Effect of transcranial DC sensorimotor cortex stimulation on somatosensory evoked potentials in humans.Clin Neurophysiol. 2004; 115: 456-460
- The effect of anodal transcranial direct current stimulation over the primary motor or somatosensory cortices on somatosensory evoked magnetic fields.Clin Neurophysiol. 2014; https://doi.org/10.1016/j.clinph.2014.04.014
- The assessment and analysis of handedness: the Edinburgh inventory.Neuropsychologia. 1971; 9: 97-113
- A proposed mechanism for the action of strong static magnetic fields on biomembranes.Int J Neurosci. 1993; 73: 115-119
- Modification of spontaneous unit discharge in the lateral geniculate body by a magnetic field.Exp Neurol. 1990; 108: 261-265
- Inhibition of calcium channel activation in GH3 cells by static magnetic fields.Biochim Biophys Acta. 1996; 1282: 149-155
- Mechanism of action of moderate-intensity static magnetic fields on biological systems.Cell Biochem Biophys. 2003; 39: 163-173
- Effect of a 125 mT static magnetic field on the kinetics of voltage activated Na+ channels in GH3 cells.Bioelectromagnetics. 2003; 24: 517-523
- Magnetic field influence on central nervous system function.Exp Neurol. 1987; 95: 679-687
- Measurement and analysis of static magnetic fields that block action potentials in cultured neurons.Bioelectromagnetics. 1995; 16: 197-206
- Effects of moderate static magnetic fields on the voltage-gated sodium and calcium channel currents in trigeminal ganglion neurons.Electromagn Biol Med. 2014; (PMID: 2471274)
- Blockade of sensory neuron action potentials by a static magnetic field in the 10 mT range.Bioelectromagnetics. 1995; 16: 20-32
- Effect of static magnetic fields on the amplitude of action potential in the lateral giant neuron of crayfish.Int J Radiat Biol. 2004; 80: 699-708
- Frequency-dependent requirement for calcium store-operated mechanisms in induction of homosynaptic long-term depression at hippocampus CA1 synapses.Eur J Neurosci. 2004; 19: 2881-2887
- Transcranial static magnetic field stimulation in man: making things as simple as possible?.J Physiol. 2011; 589: 5917-5918
- Magnetic field strength and reproducibility of neodymium magnets useful for transcranial static magnetic field stimulation of the human cortex.Neuromodulation. 2014; 17: 438-441
- Current source-density method and application in cat cerebral cortex: investigation of evoked potentials and EEG phenomena.Physiol Rev. 1985; 65: 37-100
- Corticomotor excitability induced by anodal transcranial direct current stimulation with and without non-exhaustive movement.Brain Res. 2013; 1529: 83-91
- Towards unravelling task-related modulations of neuroplastic changes induced in the human motor cortex.Eur J Neurosci. 2007; 26: 2687-2691
- Are the after-effects of low-frequency rTMS on motor cortex excitability due to changes in the efficacy of cortical synapses?.Clin Neurophysiol. 2001; 112: 2138-2145
- Human cortical potentials evoked by stimulation of the median nerve. I. Cytoarchitectonic areas generating short-latency activity.J Neurophysiol. 1989; 62: 694-710
- Spatial dynamics of population activities at S1 after median and ulnar nerve stimulation revisited: an MEG study.Neuroimage. 2006; 32: 1024-1031
- Differential generators for N20m and P35m responses to median nerve stimulation.Neuroimage. 2005; 25: 1090-1099
- Potentials evoked in human and monkey cerebral cortex by stimulation of the median nerve. A review of scalp and intracranial recordings.Brain. 1991; 114: 2465-2503
- Color imaging of parietal and frontal somatosensory potential fields evoked by stimulation of median or posterior tibial nerve in man.Electroencephalogr Clin Neurophysiol. 1985; 62: 1-17
- Neuromagnetic evidence of pre- and post-central cortical sources of somatosensory evoked responses.Electroencephalogr Clin Neurophysiol. 1996; 100: 44-50
- Pre-movement gating of somatosensory-evoked potentials by self-initiated movements: the effects of ageing and its implication.Clin Neurophysiol. 2009; 120: 1143-1148
- Recent advances in the treatment of chronic pain with non-invasive brain stimulation techniques.Lancet Neurol. 2007; 6: 188-191
- Therapeutic effects of non-invasive brain stimulation with direct currents (tDCS) in neuropsychiatric diseases.Neuroimage. 2014; 85: 948-960
- The use of repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) to relieve pain.Brain Stimul. 2008; 1: 337-344
- Non-invasive brain stimulation techniques for chronic pain.Cochrane Database Syst Rev. 2014; 4: CD008208
Published online: September 29, 2014
Accepted: September 23, 2014
Received in revised form: September 20, 2014
Received: July 14, 2014
This work was supported in part by a Grant-in-Aid for Scientific Research (C) No. 25350631 from the Japan Society for the Promotion of Science and by a Grant-in-Aid for Developed Research (B) from Niigata University of Health and Welfare.
© 2014 Elsevier Inc. Published by Elsevier Inc. All rights reserved.