Inactivation mode of sodium channels defines the different maximal firing rates of conventional versus atypical midbrain dopamine neurons
Fig 6
Calibration of Electrophysiological Profile of Atypical and Conventional Model Dopamine Cells Compared to Experimental Data from the Literature.
A. Atypical Model. A1. Spontaneous pacemaking at 5 Hz. A2. Single action potential from A1 with a peak of 11 mV, width of 5 ms at -30 mV, and minimum AHP depth of -51 mV. A3. Phase plot of dV/dt vs V. A4. Response to a 2 s, 25 pA hyperpolarization. B. Conventional model. B1. Spontaneous pacemaking at 2 Hz. B2. Single action potential from B1 with a width of 3 ms at -30 mV, peak amplitude of 28 mV and minimum AHP of -64 mV. B3. Phase plot of dV/dt vs V. B4. Response to a 2 s, 75 pA hyperpolarization. C1-C4. Same protocol as A1-A4 except recorded from an identified mesocortical VTA atypical dopamine neuron. D1-D4. Same protocol as B1-B4 except recorded from an identified mesostriatal SN conventional dopamine neuron. E- H, Responses from a hyperpolarized, silent state to depolarizing current ramps. E. Atypical model. E1. Response to 50 pA triangular ramp. E2. Response to 100 pA ramp. F1-F2. same protocol as E1-E2 as except recorded from an identified mesolimbic medial shell projecting atypical dopamine neuron. G. Conventional model. G1. Response to a 50 pA triangular ramp. G2. Response to 100 pA triangular ramp. H1-H2. same protocol as G1-G2 except recorded from an identified mesostriatal projecting conventional dopamine neuron. C, D, F and H were modified with permission from Figs 4A–4D and 5B and 5C in the complete Elsevier source [10].