"Distinctively different with the case observed in Na v 1.2α, BmK AS could move the voltage dependent activation of Na v 1.2 (α + β1) towards depolarization in a linear dose-dependent way ( xref , right, Pre AS): Prominent for 100 nM ( Δ V 1/2 = 6.43 mV, P < 0.001) and 10 nM ( Δ V 1/2 = 6.03 mV, P < 0.005), but less significant for 1 nM ( Δ V 1/2 = 2.05 mV, P < 0.05) ( xref and xref )."
"The transmembrane segments of the conserved homologous domains were shown (by site-directed mutagenesis and expression studies) to be involved in the voltage-dependent activation of sodium channels and cation transport [56–58] ."
"The S4 segments serve as voltage sensors to initiate the voltage-dependent activation of sodium channels by moving outward under the influence of the electric field, thereby imposing a conformational change leading to channel activation [ xref ]."
"Loss of Na(V)1.1 did not change voltage-dependent activation or inactivation of sodium channels in hippocampal neurons."
"We further identified that changes in neuronal currents were originated from temperature-induced shifts in voltage-dependent activation and inactivation of Na and K channels."
"The voltage-dependent activation of sodium channels is essential for the generation of the upstroke phase of the action potential in most excitable cells."
"Further, we observed no difference in I Na voltage-dependent activation, steady-state voltage-dependent inactivation, or time-dependent recovery between WT and B56α KO myocytes ( xref ; p=N.S.)."
"However, patch clamp recordings and Na + imaging studies of the AIS suggest that the density of functional Na + channels, while higher in the AIS than in the soma, may not be as high as suggested from immunohistochemistry, and that the lower threshold for AP initiation results from a hyperpolarized shift in I Na voltage-dependent activation and the presence of I NaP ( xref ; xref ; xref )."
"Similar to the case of chimera ChD3, in the presence of 2 µM BmK IT2 and a 25 ms prepulse, the voltage-dependent activation of L(Dm)Na v 1.2 displayed a mild but significant shift with ΔV 1/2 of about −5 mV (p<0.05, n = 8, xref and xref )."
"Thus, PKA phosphorylation largely attenuated the effect of BmK AS on voltage-dependent activation of Na v 1.2 either co-expressed with β1 subunit or not."
"In accordance with the previous reports, the voltage-dependent activation and inactivation of Na v 1.2α were not affected by the PKA regulation xref , which held to be true for the case of Na v 1.2α co-expression with the β1 subunit as well."
"The sodium current showed voltage-dependent activation and inactivation."
"xref describes the effects of the β1 subunit on the voltage-dependent activation of Na v 1.6 sodium channels expressed in HEK293 cells. xref shows families of sodium currents, recorded using the indicated pulse protocol, from an individual representative cell expressing rat Na v 1.6 sodium channels and current – voltage plot of the peak transient sodium currents in these traces. xref shows sodium current traces and current – voltage relationships from an individual representative cell expressing Na v 1.6β1 sodium channels. xref shows conductance – voltage plots of data obtained from multiple cells expressing rat Na v 1.6 sodium channels either in the absence or presence of the β1 subunit, and xref summarizes the statistical analysis of these data."
"Loss of Na V 1.1 did not change voltage-dependent activation or inactivation of sodium channels in hippocampal neurons ( xref )."
"Voltage-dependent activation or inactivation of sodium channels was unchanged ( xref )."
"Persistent inflammation leading to nociception also induced time-dependent changes in Aβ-fiber neuron excitability by shifting the voltage-dependent activation of Na v 1.8 in the hyperpolarizing direction, thus decreasing the current threshold for triggering action potentials."
"While the voltage-dependent activation of Na v 1.5 or Na v 1.7 was not affected by mexiletine and lidocaine, the steady-state fast and slow inactivation of Na v 1.5 and Na v 1.7 were significantly shifted to hyperpolarized direction by either mexiletine or lidocaine in dose-dependent manner."
"We found that: (1) some chemical mediators (e.g., adenosine 5'-triphosphate) produce a reduction or loss of superexcitability together with increased axonal excitability, indicating membrane depolarization; (2) blockade of axonal hyperpolarization-activated (Ih) currents produces an enhancement of superexcitability together with a decreased excitability, indicating membrane hyperpolarization; and (3) application of calcium produces an increase in membrane threshold without an alteration in superexcitability, indicating a non-specific increase in surface charge and a change in the voltage-dependent activation of sodium channels."
"The biophysical origin of such effect is believed to be the differential kinetics of the voltage-dependent activation and inactivation of sodium and potassium channels on the neuron membrane (for further details, see xref )."
"To examine the effects of mexiletine and lidocaine on channel gating properties, we started recording of voltage-dependent activation of Na v 1.5 and Na v 1.7 channels stably expressed in HEK293 cells."
"Their actions are facilitated by the micro-agatoxins, which shift voltage-dependent activation of neuronal sodium channels to more negative potentials, causing spontaneous transmitter release and repetitive action potentials."
"Despite the complete removal of inactivation by NBA, the voltage-dependent activation of sodium channels remains unaltered as determined by (a) sodium current turn-on kinetics, (b) sodium tail current kinetics, (c) voltage dependence of steady-state activation, and (d) sensitivity of sodium channels to external calcium concentration."
"The ionic conductances that are modulated by cholinergic receptor activation were assessed in voltage clamp experiments in the presence of TTX (0.5 µM) and ZD7288 (50 µM) to block voltage-dependent activation of sodium channels and the hyperpolarization-activated current I h , respectively."
"Considering the fact that there may be an offset in I-V curve due to the variation in reversal potential (Vrev), the G-V relationship was further assessed to analyze the modulation of BmK AS on voltage-dependent activation of Na v 1.2 before and after PKA phosphorylation."
"Together with the electrophysiological findings showing that the intrinsic properties, such as voltage-dependent activation and inactivation of Nav1.8 sodium channels, remained unchanged after the inoculation of tumor cells, the increased expression of Nav1.8 on the cell membrane provides a possible explanation for the enhanced density of Nav1.8- mediated sodium current in the DRG neurons of MRMT-1-treated rats, which actually represents the functional upregulation of Nav1.8 sodium channels in the DRG neurons of bone cancer rats."
"RTX-VII negatively shifted the voltage-dependent activation of the Na v 1.3/1.5 DII chimera and increased the I NaT at voltages ranging from −50 mV to 5 mV ( xref )."
"The parameters m , n and h are dynamic variables that describe the voltage-dependent activation of sodium and potassium channels, and the sodium channel deactivation after spike initiation, respectively."
"As shown in xref , myh10 coexpression hyperpolarized voltage-dependent activation of Na v 1.8 channels."
"When electrotonic propagation from the neighboring cells depolarizes the cell membrane to reach the threshold for Na + channel voltage-dependent activation, a large number of channels open giving rise to a huge depolarizing current (∼20–30 nA/pF at peak), which determines the upstroke phase of the AP."
"In this study, the effects of BmK AS, a sodium channel-specific modulator from Chinese scorpion Buthus martensi Karsch, on the voltage-dependent activation and inactivation of Na v 1.2 were examined before and after PKA activation."
"The voltage dependent activation of deglycosylated Na v 1.2 was significantly shifted to more negative direction by BmK I, contrary to the little effects on the glycosylated ones."
"Voltage-dependent activation of sodium channels depends on movement of “electrically charged particles” across the cell membrane through the transmembrane electric field [ xref ]."
"Bennett [30] suggested that a glycosylated structure is important in the voltage-dependent activation of cardiac sodium channels that in turn may alter propagation of the action potential and hence result in myocardial contraction."
"These results support the hypothesis that veratridine, in small concentrations, induces a slow voltage-dependent activation of TTX-sensitive sodium channels, independent of the fast activating and inactivating sodium channels involved in action potential generation."
"Voltage-dependent activation and inactivation of Na v 1.4, but not Na v 1.5, shifts when expressed in cells incapable of sialylation, indicating not all VGSCs are affected equally ( xref )."
"Together the data show that rSkM1 and hH1 activation mechanisms are different and are the first to suggest a role for a cytoplasmic structure in the voltage-dependent activation of cardiac sodium channels."