• dorsal root gan
  • The dorsal root ganglion of lumbar 4-5 of rats with bone cancer were shown to have up-regulation of Nav1.8 and Nav1.9 mRNA expression as well as an increase in total number of these alpha subunits. (wikipedia.org)
  • Topical menthol blocks both Nav1.8 and Nav1.9 channels in the dorsal root ganglion. (wikipedia.org)
  • type
  • After 4 days of culture, an increase of the NaV1.5 channel type was observed. (deepdyve.com)
  • The protein encoded by the gene SCN4B in humans is one of several sodium channel beta subunits, type IV. (epfl.ch)
  • One type of mutation of the epsilon subunit of the AChR introduces an Arg into the binding site at the α/ε subunit interface of the receptor. (wikipedia.org)
  • Expression of C121W mutant along with wild-type α subunits produces current indistinguishable from that through α subunits alone. (wikipedia.org)
  • Further investigation of this mutation has indicated that it results in decreased frequency dependent rundown and, thus, likely hyperexcitability when compared to cells expressing the wild-type subunit. (wikipedia.org)
  • A 10 Hz stimulation of wild-type channels causes current to decrease to approximately 70% of maximum whereas the same stimulation of mutant channels results in rundown to 90% of maximum. (wikipedia.org)
  • This is caused by an expedited recovery from inactivation for mutant channels versus wild-type. (wikipedia.org)
  • The D188V mutant, for example, recovers to 90% maximal current in 200ms while wild-type channels are unable to recover to this degree in >1000ms. (wikipedia.org)
  • expression
  • A critical determinant for the molecular and functional identity of axonal and dendritic segments is the restricted expression of voltage-gated ion channels (VGCs). (frontiersin.org)
  • By real-time polymerase chain reaction, we found that the expression of β subunits was also modified, but only after 7 days of culture: increase in β1 without β4 modifications. (deepdyve.com)
  • Our model is a useful tool to study the effects of denervation in adult muscle fibers in vitro and the expression of sodium channels. (deepdyve.com)
  • Nav1.2
  • We focus on specific potassium and sodium VGCs: Kv1, Kv4.2 and Kv2.1 and Nav1.2, Nav1.6, respectively. (frontiersin.org)
  • Under nonreducing conditions, b4 has a molecular mass exceeding 250 kDa because of its covalent linkage to Nav1.2a, whereas on reduction, it migrates with a molecular mass of 38 kDa, similar to the mature glycosylated forms of the other b subunits. (epfl.ch)
  • segment
  • Ion channel clustering at the axon initial segment and node of Ranvier evolved sequentially in early chordates. (epfl.ch)
  • The 4th transmembrane segment of each domain is the voltage-sensing region of the channel. (wikipedia.org)
  • The S4 segment contains many positive charges such that a high positive charge outside the cell repels the helix, keeping the channel in its closed state. (wikipedia.org)
  • Several charged residues of the VSD, in particular four arginine residues located regularly at every third position on the S4 segment, are known to move across the transmembrane field and contribute to the gating charge. (wikipedia.org)
  • Hence
  • Hence the potassium cations are well "solvated" by the protein carbonyl groups, but these same carbonyl groups are too far apart to adequately solvate the sodium cation. (wikipedia.org)
  • Hence, the passage of potassium cations through this selectivity filter is strongly favored over sodium cations. (wikipedia.org)
  • selectivity
  • The high selectivity with respect to the sodium ion is achieved in many different ways. (wikipedia.org)
  • They include the amino acid sequence (Thr-Val-Gly-Tyr-Gly) or (Thr-Val-Gly-Phe-Gly) typical to the selectivity filter of voltage-gated K+ channels. (wikipedia.org)
  • When moving through the selectivity filter of the potassium channel, the water-K+ interactions are replaced by interactions between K+ and carbonyl groups of the channel protein. (wikipedia.org)
  • The diameter of the selectivity filter is ideal for the potassium cation, but too big for the smaller sodium cation. (wikipedia.org)