Fig. 2.
Transfection of 3 sequence specific siRNAs targeting KV1.1, and exposure to 10 nM DTX-K cause similar changes in the excitability of primary sensory neurons in culture. (A) Lipofection of AlexaFluor488 labelled siRNA in a primary culture of rat dorsal root ganglion cells. Neuron in centre of the field is associated with siRNA on the membrane or within cytoplasm. Scale bar = 50 μm. (B) Regularly occurring action currents recorded through a cell-attached patch in voltage-clamp mode, without any applied polarisation, (patch depolarisation during action potentials associated with outward capacity current), in a neuron transfected with siRNAs specific for KV1.1. (C) Just sub and supra-threshold responses (light and heavy traces) to long duration current pulses in neurons exposed to control siRNA or 3 sequence specific siRNAs, upper and lower panels, respectively. Neurons held at − 90 mV in current-clamp. In the just supra-threshold response, the action potential is recruited later than in control. (D) Exposure of a single neuron to 10 nM DTX-K gives rise to similar changes in voltage-threshold as the sequence-specific siRNA. (E) KV1.1 sequence specific siRNA transfected neurons associated with more negative voltage-threshold than in control (*p = 0.016, n = 8, 8, t-test) (F) acutely applied 10 nM DTX-K shifts voltage-threshold more negative than control (*p = 0.014, n = 7, paired t-test).