Fig. 2.

Effect of M-GFP infection on Na⁺ currents in differentiated ND7/23 cells. (A) Typical family of Na⁺ currents generated in a differentiated ND7/23 following a series of voltage steps from a holding potential of −100 mV. Recordings from control (non-treated) and treated cells were performed at the end of the 3 d period following latency establishment. In this and subsequent figures, the voltage step protocol is shown below the current trace. (B) Comparison of cell capacitance in differentiated ND7/23 cells following M-GFP infection and treatment with ACV, TNF-α, or IL-6. Note that infection of differentiated ND7/23 with M-GFP had no significant effect on cell capacitance even in the presence of ACV or TNF-α. However, following latency establishment and treatment with IL-6 there is a significant increase in cell capacitance (** denotes p ≤ 0.05 vs. ACV pre-treated cells). The number of cells recorded under each condition is presented in parenthesis from at least 3 different cell cultures. (C) Mean Na⁺ current densities generated in differentiated ND7/23 cells following M-GFP infection (with or without ACV) and treatment with TNF-α or IL-6. Na⁺ current densities were calculated from the peak current amplitude generated by depolarizing voltage steps from a holding potential of −100 mV (* denotes p ≤ 0.05 vs. control (non-treated) cells; ** denotes p ≤ 0.05 vs. ACV pre-treated cells; *** denotes p ≤ 0.05 vs. M-GFP infected cells pre-treated with ACV; ns denotes no significant difference). (D-E) Density plot of Na⁺ current densities generated in differentiated ND7/23 cells during latency establishment with or without TNF-α. Treatment of ND7/23 cells with TNF-α during latency establishment caused an increase in current densities in the range of 1 to < 100 or > 100 pA/pF. (F) Current-voltage relationship in ACV pre-treated cells and following latency establishment and treatment with TNF-α. There is no significant shift in the voltage dependence of Na⁺currents following treatment with TNF-α compared to ACV pre-treated cells