Figure 10: Dnmt3a overexpression reduces total Kv current and increases the excitability in the injected DRG neurons 5–8 weeks after microinjection of AAV5-GFP (Control) or AAV5-Dnmt3a (DNMT3a) into the unilateral L4 and L5 DRG of rats.
(a) Representative traces of total Kv currents before or after bath perfusion of 100 nM maurotoxin (MTX) in the large DRG neurons. (b) I–V curves before or after 100 nM MTX treatment in the large DRG neurons from control (n=17 neurons from 7 rats) and DNMT3a-treated (n=25 neurons from 9 rats) groups. One-way ANOVA (current density versus. group) followed by post hoc Tukey test, Fgroup (1, 13)=145.1. *P<0.05, **P<0.01 versus the DNMT3a-treated group. (c) At +50 mV, reduction in total Kv current in the large DRG neurons after MTX treatment was greater in the control group than in the DNMT3a-treated group. *P<0.05 versus control group by two-tailed unpaired Student’s t-test. (d,e) Resting membrane potential (d) and current threshold for pulses (Ithreshold, e). n=25 large, 25 medium and 16 small neurons from control group (8 rats). n=22 large, 24 medium and 16 small neurons from the DNMT3a-treated group (10 rats). *P<0.05, **P<0.01 versus the corresponding control group by two-tailed unpaired Student’s t-test. (f) Representative traces of evoked action potentials in DRG neurons. (g–i) Numbers of evoked action potentials from control and DNMT3a-treated groups after application of different currents as indicated. Numbers of the recorded cells are the same as in d. Two-way ANOVA (effect versus. group × stimulation interaction) followed by post hoc Tukey test, Fgroup (1, 13)=98.3 for large, Fgroup (1, 13)=91.4 for medium and Fgroup (1, 13)=134.9 for small. *P<0.05, **P<0.01 versus the same stimulation intensity in the control group.
