Voltage Gated Ion Channels

Previous studies concerned the excitation process of giant nerve fibres in the squid where high resolution techniques were developed to study the so-called gating current. Interest focussed on the inactivation process which is pivotal for the termination of the action potential in nerve and muscle. Evidence for the voltage dependence of the inactivation process was obtained in squid. These studies are now followed at heterologously expressed sodium channels in Xenopus oocytes. Using high expression cRNA and an optimised voltage-clamp, large gating currents have been measured and allow now detailed stucture-function studies of wild-type and mutated channels on the molecular level; mutations include clinically known defects of inactivation as well as specific sites in the molecular gating machinery

• Voltage clamp set-ups for different preparations
• Patch-clamp and two-electrode voltage-clamp of Xenopus oocytes
• Molecular-biology lab for the efficient construction of cRNA coding for mutant channels
• Collaboration with the producer of our fast two-electrode oocyte voltage-clamp for further improvement to attack specific questions; H.R. Polder, www.npielectronic.com
• Fast and high digital resolution A/D-D/A interfaces for computer control of experiments
• Well trained workshop to build dedicated preparation chambers
• GFP-labelling of ion-channels to follow expression in oocytes