Ca2+ channel dynamics explain the nonlinear neuroplasticity induction by cathodal transcranial direct current stimulation over the primary motor cortex
| Autor: | Desmond Agboada, Michael A. Nitsche, Min-Fang Kuo, Lorena Melo, Mohsen Mosayebi-Samani |
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| Rok vydání: | 2020 |
| Předmět: |
Adult
Male medicine.drug_class medicine.medical_treatment Stimulation Calcium channel blocker Transcranial Direct Current Stimulation Young Adult 03 medical and health sciences 0302 clinical medicine Double-Blind Method Neuroplasticity medicine Humans Pharmacology (medical) Electrodes Flunarizine Biological Psychiatry Pharmacology Cross-Over Studies Neuronal Plasticity Dose-Response Relationship Drug Transcranial direct-current stimulation business.industry Motor Cortex Calcium Channel Blockers Evoked Potentials Motor 030227 psychiatry Psychiatry and Mental health medicine.anatomical_structure Neurology NMDA receptor Female Calcium Channels Neurology (clinical) Primary motor cortex business Neuroscience 030217 neurology & neurosurgery medicine.drug Motor cortex |
| Zdroj: | European Neuropsychopharmacology. 38:63-72 |
| ISSN: | 0924-977X |
| Popis: | Transcranial direct current stimulation (tDCS) induces polarity-dependent neuroplasticity: with conventional protocols, anodal tDCS results in excitability enhancement while cathodal stimulation reduces excitability. However, partially non-linear responses are observed with increased stimulation intensity and/or duration. Cathodal tDCS with 2 mA for 20 min reverses the excitability-diminishing plasticity induced by stimulation with 1 mA into excitation, while cathodal tDCS with 3 mA again results in excitability diminution. Since tDCS generates NMDA receptor-dependent neuroplasticity, such non-linearity could be explained by different levels of calcium concentration changes, which have been demonstrated in animal models to control for the directionality of plasticity. In this study, we tested the calcium dependency of non-linear cortical plasticity induced by cathodal tDCS in human subjects in a placebo controlled, double-blind and randomized design. The calcium channel blocker flunarizine was applied in low (2.5 mg), medium (5 mg) or high (10 mg) dosages before 20 min cathodal motor cortex tDCS with 3 mA in 12 young healthy subjects. After-effects of stimulation were monitored with TMS-induced motor evoked potentials (MEPs) until 2 h after stimulation. The results show that motor cortical excitability-diminishing after-effects of stimulation were unchanged, diminished, or converted to excitability enhancement with low, medium and high dosages of flunarizine. These results suggest a calcium-dependency of the directionality of tDCS-induced neuroplasticity, which may have relevant implications for future basic and clinical research. |
| Databáze: | OpenAIRE |
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