Fig. 3.

Current-voltage (I–V) relationship of spontaneous transient inward currents (STICs). Cells were studied using gramicidin-perforated, whole-cell voltage-clamp conditions. A: ICC generated STICs at a holding potential of −80 mV. Cells were stepped to various potentials from −80 to +30 mV. STICs reversed at −10 mV using Ca²⁺-containing physiological salt solution (CaPSS) as the external solution (Solution I) and K⁺-rich solution (Solution II, see Table 2) as the pipette solution. B: bumetanide (40 μM) was added at the black bar beneath current trace. Bumetanide reduced the amplitude of STICs at −80 mV and shifted reversal of STICs to −56.0 ± 2.9 mV. C: reducing extracellular Cl⁻ to 10 mM (low chloride, Solution III; Table 2) shifted the reversal potential of STICs to +55.0 ± 4.5 mV. D: summary I-V relationship for STICs in control (n = 6) and during bumetanide (n = 5) and low-chloride (n = 5) conditions.