Fig. 10: Activation of nicotinic cholinergic receptors modulates CSF-cN excitability.
A Representative whole-cell current traces recorded in CSF-cNs from the C, T and L segments (Left to Right) at Vh -80 mV in response to pressure application of acetylcholine (ACh, 4 mM for 500 ms). The representative currents recorded in the presence of D-tubocurarine (D-Tubo, 100–200 µM; violet traces) upon ACh applications are illustrated for each segment below the control traces. B Summary boxplots of the average amplitude of the ACh-mediated currents recorded at Vh -80 mV in control (Left) and in the presence of D-Tubo (Right) for the 3 segments of interest (C: N = 8, n = 11; T: N = 13, n = 12 and L-CSF-cNs: N = 7, n = 11). ANOVA.lme: F = 9.192, df=5 and 62, p(F) = 1.39 × 10−6 and Tukey (EMM) post hoc test to compare ACh-mediated current densities between regions (C vs. T, p = 0.1289; C vs. L, p = 0.2404 and T vs. L, p = 0.9512; black asterisk and bars) and the current densities recorded in control and in the presence of D-Tubo (CTR vs. D-Tubo, p = 1.991 × 10−8; violet bars and asterisks). C Representative traces of the membrane potential changes recorded at Vm -60 mV in current-clamp mode in C-, T- and L-CSF-cNs (Left to Right) in response to pressure application of ACh (4 mM, 500 ms). Bottom traces in violet are membrane potential changes recorded upon ACh application in the presence of D-Tubo. Shaded colored bars indicates the duration of the agonist application and dashed lines the 0 mV voltage. D1 Summary boxplots of the average depolarization levels of the membrane potential in C- (N = 4, n = 5), T- (N = 3, n = 7) and L-CSF-cNs (N = 4, n = 9) in response to pressure application of ACh. Kruskal-Wallis rank sum test: χ2 = 1.3411, d = 2, p(χ2) = 0.5114 and post hoc pairwise comparisons using Wilcoxon rank sum test with continuity correction: C vs. T, p = 1.0; C vs. L, p = 0.62 and T vs. L, p = 0.62). D2 Summary boxplots of the average number of AP triggered in CSF-cNs from the C (N = 4, n = 5), T (N = 3, n = 7) and L (N = 4, n = 9) segments in response to pressure application of ACh. Kruskal-Wallis rank sum test: χ2 = 3.1265, df=2, p(χ2) = 0.2095 and post hoc pairwise comparisons using Wilcoxon rank sum test with continuity correction: C vs. T, p = 0.36; C vs. L, p = 0.77 and T vs. L, p = 0.33). In B and D, Single data points for all the recorded cells at each level are presented with colored opened circle (same color code as above).
