Figure 3.

Effects of NMDA superfusion. Graphs in A and B show pooled data on action potentials elicited by dorsal root stimulation and intracellular current pulses in control (black symbols, n = 19) and NMDA-treated neurons (gray symbols, n = 7). Differences between groups were significant (ANOVA, p < 0.001 and p < 0.01, respectively) and resemble those obtained after a long-term inflammation (see Fig. 1). Current densities for sustained (C, n = 21 in control and n = 14 after NMDA) and transient potassium currents (E, n = 18 in control and n = 11 after NMDA) increased significantly after NMDA treatment (I_DR, slope of straight line fit, p < 0.01; I_A, Slope of Boltzmann fit, p < 0.05). Graph in D shows no effect of NMDA treatment on the activation curve for I_DR as obtained form the same sample of neurons included in C. Neither the inactivation (F, left axis) nor the activation curves (F, right axis) for transient currents were changed by NMDA treatment.