Induction of long-term potentiation-like plasticity in the primary motor cortex with repeated anodal transcranial direct current stimulation – Better effects with intensified protocols?

Noninvasive brain stimulation techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) can induce long-term potentiation-like facilitation, but whether the combination of TMS and tDCS has additive effects is unclear. To address this issue, in this randomized crossover study, we investigated the effect of preconditioning with cathodal high-definition (HD) tDCS on intermittent theta burst stimulation- (iTBS-) induced plasticity in the left motor cortex. A total of 24 healthy volunteers received preconditioning with cathodal HD-tDCS or sham intervention prior to iTBS in a random order with a washout period of 1 week. The amplitude of motor evoked potentials (MEPs) was measured at baseline and at several time points (5, 10, 15, and 30 min) after iTBS to determine the effects of the intervention on cortical plasticity. Preconditioning with cathodal HD-tDCS followed by iTBS showed a greater increase in MEP amplitude than sham cathodal HD-tDCS preconditioning and iTBS at each time postintervention point, with longer-lasting after-effects on cortical excitability. These results demonstrate that preintervention with cathodal HD-tDCS primes the motor cortex for long-term potentiation induced by iTBS and is a potential strategy for improving the clinical outcome to guide therapeutic decisions.

Download Full-text

Dysfunctional long-term potentiation-like plasticity in schizophrenia revealed by transcranial direct current stimulation

Behavioural Brain Research ◽

10.1016/j.bbr.2011.05.017 ◽

2011 ◽

Vol 224 (1) ◽

pp. 15-22 ◽

Cited By ~ 100

Author(s):

Alkomiet Hasan ◽

Michael A. Nitsche ◽

Bettina Rein ◽

Thomas Schneider-Axmann ◽

Birgit Guse ◽

...

Keyword(s):

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Long Term Potentiation ◽

Direct Current Stimulation ◽

Term Potentiation

Download Full-text

Enhancing Plasticity Mechanisms in the Mouse Motor Cortex by Anodal Transcranial Direct-Current Stimulation: The Contribution of Nitric Oxide Signaling

Cerebral Cortex ◽

10.1093/cercor/bhz288 ◽

2019 ◽

Vol 30 (5) ◽

pp. 2972-2985 ◽

Cited By ~ 4

Author(s):

Saviana Antonella Barbati ◽

Sara Cocco ◽

Valentina Longo ◽

Matteo Spinelli ◽

Katia Gironi ◽

...

Keyword(s):

Nitric Oxide ◽

Motor Cortex ◽

Synaptic Transmission ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Molecular Mechanisms ◽

Primary Motor Cortex ◽

Long Term Potentiation ◽

Anodal Tdcs ◽

Direct Current Stimulation

Abstract Consistent body of evidence shows that transcranial direct-current stimulation (tDCS) over the primary motor cortex (M1) facilitates motor learning and promotes recovery after stroke. However, the knowledge of molecular mechanisms behind tDCS effects needs to be deepened for a more rational use of this technique in clinical settings. Here we characterized the effects of anodal tDCS of M1, focusing on its impact on glutamatergic synaptic transmission and plasticity. Mice subjected to tDCS displayed increased long-term potentiation (LTP) and enhanced basal synaptic transmission at layer II/III horizontal connections. They performed better than sham-stimulated mice in the single-pellet reaching task and exhibited increased forelimb strength. Dendritic spine density of layer II/III pyramidal neurons was also increased by tDCS. At molecular level, tDCS enhanced: 1) BDNF expression, 2) phosphorylation of CREB, CaMKII, and GluA1, and 3) S-nitrosylation of GluA1 and HDAC2. Blockade of nitric oxide synthesis by L-NAME prevented the tDCS-induced enhancement of GluA1 phosphorylation at Ser831 and BDNF levels, as well as of miniature excitatory postsynaptic current (mEPSC) frequency, LTP and reaching performance. Collectively, these findings demonstrate that anodal tDCS engages plasticity mechanisms in the M1 and highlight a role for nitric oxide (NO) as a novel mediator of tDCS effects.

Download Full-text

Transcranial direct current stimulation induces long-term potentiation-like plasticity in the human visual cortex

Translational Psychiatry ◽

10.1038/s41398-020-01134-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Lukas Frase ◽

Lydia Mertens ◽

Arno Krahl ◽

Kriti Bhatia ◽

Bernd Feige ◽

...

Keyword(s):

Psychiatric Disorders ◽

Mechanism Of Action ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Long Term Potentiation ◽

Constant Current ◽

Direct Current Stimulation ◽

Term Potentiation ◽

Significant Difference

AbstractTranscranial direct current stimulation (tDCS) is increasingly used as a form of noninvasive brain stimulation to treat psychiatric disorders; however, its mechanism of action remains unclear. Prolonged visual stimulation (PVS) can enhance evoked EEG potentials (visually evoked potentials, VEPs) and has been proposed as a tool to examine long-term potentiation (LTP) in humans. The objective of the current study was to induce and analyze VEP plasticity and examine whether tDCS could either modulate or mimic plasticity changes induced by PVS. Thirty-eight healthy participants received tDCS, PVS, either treatment combined or neither treatment, with stimulation sessions being separated by one week. One session consisted of a baseline VEP measurement, one stimulation block, and six test VEP measurements. For PVS, a checkerboard reversal pattern was presented, and for tDCS, a constant current of 1 mA was applied via each bioccipital anodal target electrode for 10 min (Fig. S1). Both stimulation types decreased amplitudes of C1 compared to no stimulation (F = 10.1; p = 0.002) and led to a significantly smaller increase (PVS) or even decrease (tDCS) in N1 compared to no stimulation (F = 4.7; p = 0.034). While all stimulation types increased P1 amplitudes, the linear mixed effects model did not detect a significant difference between active stimulation and no stimulation. Combined stimulation induced sustained plastic modulation of C1 and N1 but with a smaller effect size than what would be expected for an additive effect. The results demonstrate that tDCS can directly induce LTP-like plasticity in the human cortex and suggest a mechanism of action of tDCS relying on the restoration of dysregulated synaptic plasticity in psychiatric disorders such as depression and schizophrenia.

Download Full-text

Non-linear effects of cathodal transcranial direct current stimulation (tDCS) of the primary motor cortex on implicit motor learning

Experimental Brain Research ◽

10.1007/s00221-019-05477-3 ◽

2019 ◽

Vol 237 (4) ◽

pp. 919-925 ◽

Cited By ~ 4

Author(s):

Gali Shilo ◽

Michal Lavidor

Keyword(s):

Motor Cortex ◽

Motor Learning ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Primary Motor Cortex ◽

Direct Current Stimulation ◽

Implicit Motor Learning ◽

Non Linear ◽

Implicit Motor ◽

Linear Effects

Download Full-text

Transcranial direct current stimulation of the primary motor cortex affects cortical drive to human musculature as assessed by intermuscular coherence

The Journal of Physiology ◽

10.1113/jphysiol.2006.116939 ◽

2006 ◽

Vol 577 (3) ◽

pp. 795-803 ◽

Cited By ~ 39

Author(s):

Hollie A. Power ◽

Jonathan A. Norton ◽

Cheryl L. Porter ◽

Zoe Doyle ◽

Isaiah Hui ◽

...

Keyword(s):

Motor Cortex ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Primary Motor Cortex ◽

Direct Current Stimulation ◽

Intermuscular Coherence ◽

Stimulation Of

Download Full-text

Comparison of repeated transcranial stimulation and transcranial direct-current stimulation on primary motor cortex excitability and inhibition: A pilot study

Movement & Sport Sciences - Science & Motricité ◽

10.1051/sm/2018001 ◽

2018 ◽

pp. 59-67 ◽

Cited By ~ 1

Author(s):

Vincent Cabibel ◽

Makii Muthalib ◽

Jérôme Froger ◽

Stéphane Perrey

Keyword(s):

Pilot Study ◽

Motor Cortex ◽

Direct Current ◽

Transcranial Direct Current Stimulation ◽

Primary Motor Cortex ◽

Motor Evoked Potentials ◽

High Definition ◽

Direct Current Stimulation ◽

Motor Cortex Excitability ◽

The Right

Repeated transcranial magnetic stimulation (rTMS) is a well-known clinical neuromodulation technique, but transcranial direct-current stimulation (tDCS) is rapidly growing interest for neurorehabilitation applications. Both methods (contralesional hemisphere inhibitory low-frequency: LF-rTMS or lesional hemisphere excitatory anodal: a-tDCS) have been employed to modify the interhemispheric imbalance following stroke. The aim of this pilot study was to compare aHD-tDCS (anodal high-definition tDCS) of the left M1 (2 mA, 20 min) and LF-rTMS of the right M1 (1 Hz, 20 min) to enhance excitability and reduce inhibition of the left primary motor cortex (M1) in five healthy subjects. Single-pulse TMS was used to elicit resting and active (low level muscle contraction, 5% of maximal electromyographic signal) motor-evoked potentials (MEPs) and cortical silent periods (CSPs) from the right and left extensor carpi radialis muscles at Baseline, immediately and 20 min (Post-Stim-20) after the end of each stimulation protocol. LF-rTMS or aHD-tDCS significantly increased right M1 resting and active MEP amplitude at Post-Stim-20 without any CSP modulation and with no difference between methods. In conclusion, this pilot study reported unexpected M1 excitability changes, which most likely stems from variability, which is a major concern in the field to consider.

Download Full-text