A special non-invasive and painless form of electrostimulation activates particular areas of the brain. A pin-point activation of our tactile sense offers exciting therapy approaches.
Study with transcranial direct current stimulation
Scientists of the Neurological Clinic at Bochum's University Clinic Bergmannsheil applied transcranial direct current stimulation to the somatosensory cortex of 37 healthy study participants. They then investigated how this procedure affects neuronal activity. "Our study shows that a positive charge leads to an increase in neuronal activity in the somatosensory cortex, while a negative charge inhibits such activity. This corresponds with previous studies which showed similar results for motor and visual areas of the brain," explains study leader Dr. med. Matthias Sczesny-Kaiser.
Electrostimulation increases and inhibits brain activity
Transcranial direct current stimulation is an electrostimulation of the brain. During the procedure a very low current is applied through electrodes on the scalp. This influences the excitability of nerve cells and changes neuronal activity. The direction of change depends on the polarity of the applied charge: the positively charged anode increases neuronal excitability, the negatively charged cathode inhibits it. The method merely causes a tingling sensation on the scalp and is already successfully being applied in the therapy of depression or stroke.
Researchers investigate somatosensory cortex
The researchers in Bochum were able to show that this particular kind of electrostimulation leads to polarity-dependent changes in the somatosensory cortex. This area of the brain processes impressions of more than 20 different receptor types. They all serve our bodily perception. Besides our sense of touch, other sensations like temperature, pressure or pain are encoded in this brain area. The results of the study have now been published in the journal "Frontiers in Human Neuroscience".
Results may lead to new therapy
Further research must now reveal whether the change in neuronal activity also leads to a change in sensory perception. Bochum's neuroscientists also want to find out how long the effect lasts. Their results could lead to new approaches in the treatment of those with a loss of tactile acuity or pain patients.
The study was conducted as part of the work of Collaborative Research Centre 874, which is funded by the Deutsche Forschungsgemeinschaft. Working in several projects at the Ruhr University, the interdisciplinary research consortium aims to find out how sensory perception is processed in the brain.
Reference: R. Rehmann, M. Sczesny-Kaiser, M. Lenz, T. Gucia, A. Schliesing, P. Schwenkreis, M. Tegenthoff and O. Höffken (2016): Polarity-specific cortical effects of transcranial direct current stimulation in primary somatosensory cortex of healthy humans. Frontiers in Human Neuroscience, DOI:10.3389/fnhum.2016.00208.
Dr. Matthias Sczesny-Kaiser
Neurologische Universitätsklinik und Poliklinik
Tel: +49 - (0)234 - 302 - 3258
Text: Annegret Kalus