Stimulation of Neurons and Astrocytes via Temporally Interfering Electric Fields

A novel non-invasive electrical stimulation method, temporal interference stimulation (TIS), has been proposed to enable spatially steerable stimulation and to selectively activate different brain regions. However, TIS has not been studied with cell cultures that can provide an in-depth assessment of its effects on neuronal cells. We successfully established an in vitro TIS setup using rat cortical neurons on microelectrode arrays. Stimulations involved 1) TIS with 653 Hz and 643 Hz, resulting in a 10 Hz frequency envelope, 2) low-frequency stimulation (LFS) at 10 Hz, 3) high-frequency stimulation (HFS) at 653 Hz, and 4) no electrical stimulation (control/sham). HFS and LFS had the least effect on neuronal activity, but TIS elicited neuronal electrophysiological responses, especially 24 hours after stimulation. We also assessed TIS in neuron-astrocyte co-cultures. Interestingly, co-cultures seemed to counteract the TIS effects. Hence, our findings deepen the current understanding of the electrical modulation of neurons during TIS. ### Competing Interest Statement A.H. is partially employed with neuroConn GmbH. Otherwise, the authors declare no conflict of interest.