tetrodotoxin binding activity and a protein of ‫072ف‬ kDa (Agnew et al., 1980). Subsequent purification studies showed that the sodium channel from mammalian brain is a complex of ␣ al., 1982), the tetrodotoxin-binding component of the sodium channel purified from eel electroplax is a single Voltage-gated sodium channels are responsible for the protein of 270 kDa (Miller et al., 1983), and the ...

The effects of site-directed antibodies on single sodium channel currents in excised membrane patches from rat brain neurons have been examined. Of six antibodies directed against different intracellular domains of the sodium channel alpha subunit, only an antibody directed against a highly conserved intracellular segment between homologous transmembrane domains III and IV induced late single c...

Although classical neurophysiological doctrine rested on the concept of the sodium channel, it is now clear that there are nearly a dozen sodium channel genes, each encoding a molecularly distinct channel. Different repertoires of channels endow different types of neurons with distinct transduction and encoding properties. Sodium channel expression is highly dynamic, exhibiting plasticity at bo...

We have previously presented evidence that electrical activity and increased cytosolic calcium reduce the density of sarcolemmal tetrodotoxin (TTX)-sensitive sodium channels in cultured rat muscle cells (Sherman, S. J., and W. A. Catterall (1984) Proc. Natl. Acad. Sci. U. S. A. 81: 262-266). We show here that growth of cells in ryanodine has a biphasic effect on sodium channel number. At low co...

Sodium-channel blockers act by slowing sodium influx into myocytes through voltage gated channels. Many substances have sodium-channel blocking properties and many others show this effect when taken in overdose. Sodium-channel blocker poisoning, associated with a high death rate, is characterized by a variety of clinical presentation, depending on the pharmaceutical agent involved. Sodium bicar...

Late openings of sodium channels were observed in outside-out patch recordings from hippocampal neurons in culture. In previous studies of such neurons, a persistent sodium current appeared to underlie the ictal epileptiform activity. All the channel currents were blocked by tetrodotoxin. In addition to the transient openings of sodium channels making up the peak sodium current, there were two ...

Neuronal growth factors regulate the expression of voltage-activated sodium current in differentiating sympathetic neurons and PC12 cells. We show that, in PC12 cells, the NGF- and FGF-induced sodium current results from increased expression of two distinct sodium channel types. Sodium current results from the rapid induction of a novel sodium channel transcript, also found in peripheral neuron...

We studied the relation of the maximal upstroke velocity (Vmax) of action potentials to the peak sodium current (INa) under voltage clamp in single, internally perfused, canine cardiac Purkinje cells under conditions that ensured membrane action potentials due only to INa. Three different methods of altering sodium channel availability were investigated: voltage-dependent inactivation, tetrodot...