P306 Calcium imaging reveals glial involvement in transcranial direct current stimulation-induced plasticity in mouse brain

• Published in: Clinical neurophysiology 2017-03, Vol.128 (3), p.e159-e160
• Main Authors: Monai, H, Ohkura, M, Tanaka, M, Oe, Y, Konno, A, Hirai, H, Mikoshiba, K, Itohara, S, Nakai, J, Iwai, Y, Hirase, H
• Format: Article
• Language: English
• Subjects: Neurology
• ISSN: 1388-2457; 1872-8952
• DOI: 10.1016/j.clinph.2016.10.413

Transcranical direct current stimulation (tDCS) is a treatment known to ameliorate various neurological conditions and enhance memory and cognition in humans. tDCS has gained traction for its potential therapeutic value; however, little is known about its mechanism of action. Using a transgenic mouse expressing G-CaMP7 in astrocytes and a subpopulation of excitatory neurons, we find that tDCS induces large-amplitude astrocytic Ca2+ surges across the entire cortex with no obvious changes in the local field potential. Moreover, sensory evoked cortical responses are enhanced after tDCS. These enhancements are dependent on the alpha-1 adrenergic receptor (A1AR) and are not observed in IP3 R2 (inositol trisphosphate receptor type 2) knockout mice, in which astrocytic Ca2+ surges are absent. Together, we propose that tDCS changes the metaplasticity of the cortex through astrocytic Ca2+ /IP3 signalling. Moreover, the stimulation parameters were found to be sufficient to alleviate a mouse model of depression by chronic restraint stress.