Slight correction (said dendrite, meant axon).
It seems to me possible that axons, being insulated conductors, can resonate, act as antennae. If so, when stimulating at their resonant frequency, or some fractional wavelength, it is feasible they can generate ionizing voltages. Axons come in lengths differing from microns to multiple centimeters.
Best regards, Horace Heffner http://www.mtaonline.net/~hheffner/
