Single-channel analysis of tetrodotoxin-sensitive and tetrodotoxin-resistant sodium channels in rat dorsal root ganglion neurons.

Tetrodotoxin-sensitive and tetrodotoxin-resistant single sodium channel currents were recorded from rat dorsal root ganglion neurons. The two types of sodium channel currents could be distinguished by the effects of predepolarization, 10 nM tetrodotoxin, and the inactivation during depolarization. Single-channel conductances were calculated to be 6.3 and 3.4 pS in the tetrodotoxin-sensitive and tetrodotoxin-resistant channels, respectively.