Predicting neural responses to intra- and extra-cranial electric brain stimulation by means of the reciprocity theorem
Fig 5
Intrinsically active cell model.
A: Macaque STN neuron from Miocinovic et al. (2006) [43]. B: The intrinsic spiking activity of the model in the absence of input. C: An electric stimulation (location marked by orange dot in panel A) at 10 Hz with a current amplitude of 100 μA, 500 μm away from the soma of the cell model. D: The somatic membrane potential of the cell under the influence of the ES in panel C, simulated through the traditional approach. E: Through the RT, we can calculate the effect of the ES in isolation, by inserting the current in panel C into the soma of a passive version of the cell model, and calculating at the ES location. The resulting amplitude of
was 2.1 mV. From the same simulation, we can calculate the input impedance of the model, and from this the equivalent somatic current amplitude of 67.6 pA needed to cause this 2.1 mV oscillation. F: The original active cell model is stimulated with an “ES proxy”, that is, by injecting this current into the soma (amplitude 67.6 pA) designed to mimic the
in panel E. This closely approximates the direct simulation (panel D).