Rapid and Reversible Block of Electrical Activity by Powerful Marine Biotoxins

Abstract
Puffer-fish poison and clam poison reversibly inhibit conduction in single nerve fiber preparation of frog in a concentration of 3 × 10-10M. In the isolated electroplax of Electrophorus electricus higher concentrations block both transmission and conduction. Neither toxin is a potent acetylcholinesterase inhibitor. The mechanism of action of these toxins in blocking transmission and conduction has not yet been established.