Figure 4.

Lanthanum mode of action. (A₁) Patch pipette filled with calcium-sensitive dye OGB1 was used to fill a SP neuron. Voltage clamp step (shown below Ca²⁺) from −70 to 0 mv (duration 100 ms) was used to trigger calcium influx measured by calcium imaging inside the region of interest (ROI) covering the cell body. (A₂, A₃) In P1–P6 mice, several drug combinations have small effect on the voltage-evoked calcium transient: TTX (1 μM) + TEA (10 mM) + 4AP (5 mM); Mibefradil (20 μM) + Verapamil (20 μM) + Diltiazem (20 μM). However, 100 μM La³⁺ inhibits calcium flux in neonatal mice. In adolescent mice (P16–P32), on the other hand, MVD inhibits calcium current (B₁) while La³⁺ has no effect (B₂, B₃). Voltage clamp step was synchronized with the first Ca²⁺ trace (Control). All subsequent traces were shifted to the right for clarity. (C₁) Spontaneus activity before and after MVD (Mibefradil [90 μM] + Verapamil [20 μM] + Diltiazem [20 μM]). (C₂) MVD has no effect on 3 parameters: event count, duration, and area.