Fig. 5. Kv4-channel density is elevated in the mouse model of medullary α-synucleinopathy.

(A) Voltage-clamp measurements of A-type currents yield voltage activation and inactivation curves and time constants of inactivation. Note that a window current flows constitutively in the subthreshold voltage range where the voltage activation and inactivation curves overlap. (B) Comparison of voltage dependency of activation and inactivation (EV: n = 11 neurons; A53T: n = 8 neurons) and channel inactivation kinetics (EV: n = 9 neurons; A53T: n = 8 neurons) between AAV-EV– (N = 6) and AAV-A53T– (N = 4) transfected mice reveals no difference. (C) Left: Example of measurements of the inactivating A-type current density (depolarization to −40 mV), which is carried by Kv4 channels, from DMV neurons transfected with either AAV-EV (black, n = 11 neurons, N = 6 mice) or AAV-A53T (red, n = 8 neurons, N = 4 mice). Areas under the curves in gray and pink, respectively, indicate that the Kv4 charge densities are significantly higher (t₁₇ = 2.57) in the DMV neurons transfected with AAV-A53T (box plots).