title: Divalent cations and temperature dependent block of impulse propagation at the frog neuromuscular junction.
abstract: End-plate potentials were recorded from superficial muscle fibers of the frog sartorius nerve-muscle preparation. Exposure of the preparation to a medium containing a high divalent cation concentration, produced a temperature dependent failure of neuromuscular transmission. Failure of transmission developed in an "all-or-none" mode and was reversed by decreasing the bath temperature or divalent cation concentration. This blockage of the neurotransmission is attributed to a presynaptic block of impulse propagation.
mesh_terms: D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000494:pharmacology; D002413:Cations, Divalent / Q000494:pharmacology*; D066298:In Vitro Techniques; D008274:Magnesium / Q000494:pharmacology; D009407:Nerve Block; D009469:Neuromuscular Junction / Q000502:physiology*; D011896:Rana temporaria; D013324:Strontium / Q000494:pharmacology; D009435:Synaptic Transmission / Q000187:drug effects; D013696:Temperature
chemical_list: D002413:Cations, Divalent; D002104:Cadmium; D008274:Magnesium; D002118:Calcium; D013324:Strontium