Fig. 1

Calibration of dopamine neuron model. a The equivalent circuit for the conductance-based model with nonlinear conductance in parallel with the membrane capacitance \(C_{\mathrm{m}}\). The maximal conductance and reversal potential of each current are indicated by \(g_{x}\) and \(E_{x}\), respectively. The arrows indicate time and voltage-dependent conductances. b Calibration of model K⁺ currents. b1 The parameters of the description of the A-type K⁺ current were adjusted to fit published voltage clamp data from nucleated membrane patches from SNc dopamine neurons (representative current traces from Fig. 11A3 of [28]). The conductance used for these simulations (120 μS/cm²) was chosen to match the amplitude of the currents from the voltage clamp data, obtained with 100 ms steps from a holding potential of −100 mV to 50 mV in increments of 10 mV. b2 The parameters of the description of the ERG-type K⁺ current were adjusted to fit published voltage clamp data (Fig. 1A of [32]) from human channels heterologously expressed in Xenopus oocytes. The conductance used for these simulations was chosen to match the amplitude of the currents from the voltage clamp data, obtained with 600 ms steps from a holding potential of −80 mV to −100 to 50 mV in increments of 10 mV. Tail currents were measured at −70 mV. c The model neuron exhibits slow pacemaker firing at 3.6 Hz under control conditions. d With \(g_{\mathrm{Na}}\) set to zero and \(I_{\mathrm{stim}}\) set to 35 pA, the model exhibits a Ca²⁺-dependent sinusoidal slow oscillatory potential (SOP)