Figure 1. Ionomycin induces inhibition of neuronal T-type and recombinant Cav3 currents.
(a–c) Extracellular application of ionomycin induces inhibition of the native T-type current in D-hair sensory neurons. (a) Effect of 10 µM ionomycin (iono) on the T-type current recorded from a D-hair sensory neuron. (b) Time course and average effect (inset) of ionomycin (n = 5). (c) Steady-state inactivation of the native T-type current before (ctrl) and after ionomycin application (n = 5). (d–f) Ionomycin induces inhibition of the recombinant Cav3.1, Cav3.2 and Cav3.3 currents. (d) Effect of ionomycin application (10 µM) on the Cav3.3 current amplitude. Average effect of ionomycin on Cav3.1, Cav3.2 and Cav3.3 currents (inset, n = 6–7 per bar). (e) Inactivation kinetics of the Cav3 currents in the absence and in the presence of ionomycin (n = 6–7 per bar). (f) Steady-state inactivation of Cav3.1, Cav3.2 and Cav3.3 currents before and after ionomycin application (n = 6–7). In (a), (b), (d) and (e), the currents were recorded at −30 mV from a holding potential (HP) of −80 mV. In (c) and (f), the currents were elicited at −30 mV from HPs ranged from −130 to −40 mV (5 s duration) and the data were fitted with the Boltzmann equation.