Figure 4
Manipulation of NOS modulates synaptic drive and excitability of the premotor interneuron A27h. (A) Voltage-clamp recordings of synaptic currents from the premotor interneuron A27h at L3 following NOS manipulation. Early administration of both 0.5 M L-NAME (n = 12) or 5 mM SNP (n = 10) increased duration of A27h synaptic currents (n = 10). (B) Quantification of the duration of A27h synaptic inputs. One-way ANOVA (F(2, 29) = 12.72, p < 0.001) followed by Bonferroni’s post-hoc test. (C) Representative traces showing the effect of NOS manipulation on AP firing recorded from A27h and elicited by a depolarizing current injection (40 pA/1 s). (D) Changes in membrane excitability of L3 A27h interneurons were determined by injection of successively greater depolarizing current pulses (Δ + 4 pA steps/1 s). A two-way ANOVA revealed a significant effect of voltage (F(13, 377) = 197.1, p < 0.001), NOS manipulation (F(2,29) = 7.005, p = 0.003), and interaction (F(26, 377) = 5.626, p < 0.001). Data are represented as mean ± SEM. **p < 0.01 and ***p < 0.001, Bonferroni’s post-hoc test, n = 10 in CTRL and 5 mM SNP, n = 12 in 0.5 M L-NAME. (E) NOS manipulation shifted the threshold potential in A27h interneurons toward more negative values. One-way ANOVA (F(2, 29) = 6.306, p = 0.0053) followed by Bonferroni’s post-hoc test.
