Figure 4

Voltage-activated sodium currents after three days in proliferation medium and further six days in differentiation medium. (A) Original current traces from cell cultured for three days under control conditions recorded in Ba²⁺ containing extracellular solution to avoid distortion of voltage-activated currents by inwardly rectifying potassium currents. (B) Current to voltage relationship of peak sodium currents shown in A. (C) Fraction of cells showing a I_Na current larger than 50 pA for each tested culture condition (control: C, pretreatment with TNF-α and IFN-γ for 48 hours:TI, control cultures treated with dexamethasone: CD, cultures co-treated with dexamethasone and TNF-α and IFN-γ for 48 hours: TID). The number of cells tested under each condition is indicated within the corresponding column. (D) Average inward current densities of the cells listed posititve for this current in (C). Note, that d9TI cells show a similar percentage of cells with inward currents of similar amplitudes as proliferating progenitor cells. The single cell showing an inward current under condition d9CD was ignored for the analysis of the average current density. The sodium current densities were not statistically significantly different from each other. Error bars denote mean ± SE.