Abstract

Transcranial direct-current stimulation (tDCS) is a non-invasive brain stimulation technique consisting in the application of weak electric currents on the scalp. Although previous studies have demonstrated the clinical value of tDCS for modulating sensory, motor, and cognitive functions, there are still huge gaps in the knowledge of the underlying physiological mechanisms. To define the immediate impact as well as the after effects of tDCS on sensory processing, we first performed electrophysiological recordings in primary somatosensory cortex (S1) of alert mice during and after administration of S1-tDCS, and followed up with immunohistochemical analysis of the stimulated brain regions. During the application of cathodal and anodal transcranial currents we observed polarity-specific bidirectional changes in the N1 component of the sensory-evoked potentials (SEPs) and associated gamma oscillations. On the other hand, 20 min of cathodal stimulation produced significant after-effects including a decreased SEP amplitude for up to 30 min, a power reduction in the 20–80 Hz range and a decrease in gamma event related synchronization (ERS). In contrast, no significant changes in SEP amplitude or power analysis were observed after anodal stimulation except for a significant increase in gamma ERS after tDCS cessation. The polarity-specific differences of these after effects were corroborated by immunohistochemical analysis, which revealed an unbalance of GAD 65–67 immunoreactivity between the stimulated versus non-stimulated S1 region only after cathodal tDCS. These results highlight the differences between immediate and after effects of tDCS, as well as the asymmetric after effects induced by anodal and cathodal stimulation.

Details

Title
Immediate and after effects of transcranial direct-current stimulation in the mouse primary somatosensory cortex
Author
Sánchez-León, Carlos A 1 ; Cordones Isabel 1 ; Ammann, Claudia 2 ; Ausín, José M 3 ; Gómez-Climent, María A 1 ; Carretero-Guillén, Alejandro 1 ; Sánchez-Garrido, Campos Guillermo 1 ; Gruart Agnès 1 ; Delgado-García, José M 1 ; Cheron, Guy 4 ; Medina, Javier F 5 ; Márquez-Ruiz, Javier 1 

 Pablo de Olavide University, Department of Physiology, Anatomy and Cell Biology, Seville, Spain (GRID:grid.15449.3d) (ISNI:0000 0001 2200 2355) 
 HM CINAC, Hospital Universitario HM Puerta del Sur, HM Hospitales, Madrid, Spain (GRID:grid.428486.4) (ISNI:0000 0004 5894 9315) 
 Universidad Politécnica de Valencia, Instituto de Investigación E Innovación en Bioingeniería, Valencia, Spain (GRID:grid.157927.f) (ISNI:0000 0004 1770 5832) 
 Université de Mons, Laboratory of Electrophysiology, Mons, Belgium (GRID:grid.8364.9) (ISNI:0000 0001 2184 581X); Université Libre de Bruxelles, Laboratory of Neurophysiology and Movement Biomechanics, ULB Neuroscience Institute, Brussels, Belgium (GRID:grid.4989.c) (ISNI:0000 0001 2348 0746) 
 Baylor College of Medicine, Department of Neuroscience, Houston, USA (GRID:grid.39382.33) (ISNI:0000 0001 2160 926X) 
Publication year
2021
Publication date
2021
Publisher
Nature Publishing Group
e-ISSN
20452322
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2486317651
Copyright
© The Author(s) 2021. This work is published under http://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.