Effects of methylmercury on the electric activity of the node of Ranvier.
The toxicity of methylmercury chloride (0.05-0.5 mM/L) to nerve fibers has been tested in vitro on a single frog's myelinated nerve fibers. The electrophysiological activity of the node of Ranvier has been recorded according to the air-gap technique. The amplitude of the action potential dies down progressively and the threshold for electric excitability increases; membrane Na+ and K+ transferences are significantly reduced. Eventually the action potentials are blocked and the membrane undergoes progressive depolarization. A recovery upon withdrawal was observed only with lower concentrations. A pretreatment with reducing agents (DTT and 2-mercaptoethanol) may delay the block of the electric activity of the node.
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D004229:Dithiothreitol / Q000494:pharmacology; D066298:In Vitro Techniques; D008767:Methylmercury Compounds / Q000633:toxicity*; D011898:Ranidae; D011901:Ranvier's Nodes / Q000187:drug effects* / Q000502:physiology
D008767:Methylmercury Compounds; D004229:Dithiothreitol