Figure 7: TRPA1 activation reduces the excitability of DRG neurons.
(a) Action potentials evoked by current injections before application (lower panel, black trace) and after washout of p-BQ (red trace) in a neuron that did not depolarize in response to application of 500 nM p-BQ (upper trace). (b) Action potentials evoked by current injections (lower panel) in a p-BQ-responsive neuron (shown in upper trace) before application of p-BQ (black trace), during the p-BQ evoked depolarization (blue trace) and after washout and complete repolarization (red trace). (c) Voltage-gated calcium currents (ICa) recorded in a p-BQ-insensitive (c) and a p-BQ-sensitive (d) DRG neuron before (lower panel, black trace) and after stimulation with p-BQ (red trace). ICa was evoked by a voltage step from −80 mV to 0 mV. (e) Voltage-gated sodium currents (INa) recorded before and after a challenge with p-BQ in a p-BQ-sensitive neuron. (f,g) Effect of p-BQ on INa density (middle panels) and conductance (bottom panels) in a p-BQ-insensitive (f) and p-BQ-sensitive neuron (g). p-BQ currents were recorded at a holding potential of −60 mV.
