TEMPORAL INTERFERENCE STIMULATION MODULATES NEURON FIRING RATE DEPENDING ON NEURONAL SUBTYPE WITH SYNAPTIC NOISE: AN IN-SILICO STUDY

Electrical Temporal Interference Stimulation (TIS) is a noninvasive neuromodulation technique that aims to target deep brain regions by generating low frequency amplitude envelopes resulting from the interference of high frequency electric fields. However, the cellular mechanisms remain incompletely understood. Here, we investigated how TIS affects the spiking dynamics of a single neuronal cell in a simulated network using biophysical computational models. We used modified multicompartment detailed neuron models from the Blue Brain Project, with inhibitory and excitatory neuronal subtypes. Neural baseline activity was generated by stochastic excitatory and inhibitory synaptic inputs. TIS electric fields were applied as two interfering carriers around 2 kHz producing 5 Hz interference envelopes. The results were compared with the results with single high frequency stimulation (HFS). TIS and HFS had equal RMS energy at the cell membrane.
Preliminary results show that TIS induced stimulation amplitude dependent (c.f., Fig. 1) modulation of neuronal firing rates. Increasing stimulation amplitude elevated firing rates, with differences between cell types. Inhibitory neurons were more sensitive to the stimulus amplitude. These patterns were consistent for all the neuron types studied for the TIS condition, whereas firing rates showed little or non-modulation in the single high-frequency condition (Fig. 1). Future analyses will incorporate a broader range of neuronal types and an expanded assessment of spiking features.
Overall, these findings show that TIS has neuronal type dependent modulatory effects at cellular level distinguishable from HFS.