Affiliations: [a] Department of Physiology, Wonkwang University College of Medicine, Iksan, South Korea
| [b] Department of Clinical Neurophysiology, University Medical Center, Georg-August-University, Goettingen, Germany
| [c]
Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany
| [d] Department of Physical and Rehabilitation Medicine, Center for Prevention and Rehabilitation, Heart Vascular Stroke Institute, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| [e] Department of Rehabilitation Medicine, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea
| [f] Department of Neurology, BG University Hospital Bergmannsheil, Ruhr-University Bochum, Germany
Correspondence:
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Corresponding author: Yong-Il Shin, M.D., Ph.D., Department of Rehabilitation Medicine, Pusan National University School of Medicine, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, Korea. Tel.: +82 55 360 4250; Fax: +82 55 360 4251; E-mail: rmshin@pusan.ac.kr.
Abstract: Background: Anodal transcranial direct current stimulation (A-tDCS) induces a long-lasting increase in cortical excitability that can increase gene transcription in the brain. Objective: The purpose of this study was to evaluate the expression of genes related to activity-dependent neuronal plasticity in the sensorimotor cortex and hippocampus of young Sprague-Dawley rats following A-tDCS. Methods: We applied A-tDCS over the right sensorimotor cortex epicranially with a circular electrode (3 mm diameter) at 250 μA for 20 min per day for 7 consecutive days. Levels of mRNA for brain-derived neurotrophic factor (BDNF), cAMP response element-binding protein (CREB), synapsin I, Ca2+/calmodulin-dependent protein kinase II (CaMKII), activity-regulated cytoskeleton-associated protein (Arc), and c-Fos were analyzed using SYBR Green quantitative real-time polymerase chain reaction (PCR). Results: We found that 7 days of unilateral A-tDCS resulted in significant increases in transcription of all plasticity-related genes tested in the ipsilateral cortex. Daily A-tDCS also resulted in a significant increase in c-Fos mRNA in the ipsilateral hippocampus. Conclusion: These results indicate that altered expression of plasticity-associated genes in the cortex and hippocampus is a molecular substrate of A-tDCS-induced neural plasticity.
Keywords: Anodal transcranial direct current stimulation, immediate-early genes, somatosensory cortex, synaptic plasticity-related genes
