In this Quick Guide, Lorentz et al. discuss the function of tetrodotoxin and its distribution in the animal kingdom.

BACKGROUND The local anesthetic properties of tetrodotoxin, a potent naturally occurring sodium channel blocker, have been recently reexamined. It was found that sciatic nerve block duration could be greatly increased and systemic toxicity greatly decreased if epinephrine was injected with tetrodotoxin. The mechanism that underlies epinephrine-mediated prolongation of tetrodotoxin nerve blocks ...

introduction: neurons in layer ii and iii of the somatosensory cortex in rats show high frequency (33 ± 13 hz) of miniature excitatory postsynaptic currents (mepscs) that their rates and amplitudes are independent of sodium channels. there are some changes in these currents in neurodegenerative and psychological disorders. regarding to well known roles of the neuromodulatory brain systems in th...

Two photoactivable derivatives of tetrodotoxin have been synthesized. Electrophysiological experiments on crab giant axons and competitive binding with [3H]-tetrodotoxin for the tetrodotoxin receptor indicate that they are only 4.5 to 7.5 times less active than tetrodotoxin itself. These compounds give a reversible block of the sodium channel in the dark but after ultraviolet irradiation they p...