ABSTRACT
The electrophysiological analysis of cloned and mutated ion channels requires the introduction of the Deoxyribonucleic acid or Ribonucleic acid molecule encoding the ion channel of interest into a cellular host. This chapter considers the relative merits and limitations of the use of the two most common methods of analysis of recombinant ion channels, microinjection and analysis in Xenopus oocytes and expression in mammalian cell lines. The Xenopus oocyte system has been used for the expression cloning of several receptors and ion channels including the substance K receptor and the glutamate GluR-Kl receptor. The oocyte expression system has also been widely used for the structure/function analysis of mutated ion channel receptors with some of the most elegant studies being performed by B. Sakmann and S. Numa in their analyses of the ion permeation properties of the nicotinic acetylcholine receptor. One finds ion channel research breakthroughs that use either Xenopus oocyte or mammalian cell expression systems.
