title: All or none block of single Na+ channels by tetrodotoxin.
abstract: The effects of tetrodotoxin on single Na+-channel currents recorded from excised patches of neuroblastoma cells were examined. Tetrodotoxin was found to cause a dose-dependent reduction in the frequency at which Na+ channels conduct during a series of depolarizations. Surviving conducting states had normal open times and current amplitudes. These effects could be explained by a model which includes initial binding of tetrodotoxin to a closed state of the channel with stable, complete block during the time the channel would normally be gated open.
authors.forename: F N
authors.initials: FN
authors.lastname: Quandt
authors.forename: J Z
authors.initials: JZ
authors.lastname: Yeh
authors.forename: T
authors.initials: T
authors.lastname: Narahashi
mesh_terms: D002460:Cell Line; D007473:Ion Channels / Q000187:drug effects*; D008564:Membrane Potentials; D008959:Models, Neurological; D009447:Neuroblastoma; D012530:Saxitoxin / Q000494:pharmacology; D012964:Sodium / Q000378:metabolism*; D013779:Tetrodotoxin / Q000494:pharmacology*
chemical_list: D007473:Ion Channels; D012530:Saxitoxin; D013779:Tetrodotoxin; D012964:Sodium