Figure 3

The mechanotransduction current can be carried by monovalent ions. (A) Mechanically activated current traces recorded from a DRG neuronal soma with a diameter of 38 μm when external solution consisted of 140 mM NaCl (with HEPES, glucose, and sucrose). Traces shown are for membrane voltages clamped at levels from -110 to +130 mV in increments of 40 mV. Probe velocity was 3.5 mm/s. (B) Mean peak current-voltage relation in sodium chloride bath solution (closed circles). The mean amplitude of peak current seen in standard solutions at -70 mV, in the same cells using the same stimulus parameters, is indicated by the open circle. (C) Current traces recorded from another neuron (41-μm diameter) in LiCl bath solution. Traces shown were recorded at command voltages of -111 to +89 mV in increments of 40 mV. Probe velocity was 3.5 mm/s. (D) Mean current-voltage relation in lithium chloride bath (closed circles). The mean amplitude of current seen in standard solutions at -70 mV, in the same cells using the same stimulus parameters, is indicated by the open circle. (E) Current traces recorded from a 37-μm-diameter DRG neuron when bath solution consisted of 140 mM KCl (with HEPES, glucose, and sucrose) at membrane voltages stepped from -109 to +91 mV in increments of 40 mV. Probe velocity was 4.1 mm/s. (F) Mean current-voltage relation in potassium chloride bath (closed circles). The mean amplitude of current seen in standard solutions at -70 mV, in the same cells using the same stimulus parameters, is indicated by the open circle. (G) Current traces recorded from a neuron (40-μm diameter) in cesium chloride bath with the membrane voltage clamped at -108 to +92 mV in increments of 40 mV. Probe velocity was 3.8 mm/s. (H) Mean current-voltage relation for MA currents in cesium chloride bath and using the potassium-based electrode solution (closed circles). The mean amplitude of current seen with the standard external solution at -70 mV, in the same cells using the same stimulus parameters, is indicated by the open circle.