Studies on Urinary Tract Infections in Children

Natural Toxins as Tools in Neurophysiology

“…It occurs in the ovaries and liver of the Japanese puffer fish, Spheroides rubripes, as well as in the embryos of the Californian newt, Taricha torosa, indeed a remarkable example of evolutionary chemical convergence. The pharmacology of tetrodotoxin has been well documented [41]. For the study of ionic permeability, tetrodotoxin has been of great value, because it selectively blocks the transmembrane flux of sodium ions, and thus the rising phase of the action potential, more so in presynaptic nerve membranes ANTAMANIDE than in postsynaptic muscle membranes.…”

“…It is surprising that the frog that produces batrachotoxin is resistant to its effects; therefore, its nerve and muscle membranes may not have toxin binding sites [63]. Likewise, desheathed nerves from the Californian newt (Taricha) and from puffer fish (Spheroides) are 30,000 and 1,000 times respectively more resistant to their own venom, tetrodotoxin, than frog (Rana pipiens) nerve [41]. The mechanism of these resistances offers a fascinating field for further study.…”