ABSTRACT
Ion channels are important for the regulation of cellular activity in a great variety of cell types from both simple and complex organisms (1). In the last two decades, technological advances in electrophysiology and molecular biology have led to great progress in ion channel research. As discussed in previous chapters in this monograph, the use of the patch-clamp method to record single-channel and whole-cell currents makes it possible to characterize the electrophysiological and pharmacological properties of ion channels and the mechanisms by which receptors and second messengers modulate ion channels (2,3). However, this technique is obviously restricted by (1) the specificity of the pharmacological tools available, (2) heterogeneity of ion channel expression and function in different cells, and (3) the extent of available knowledge about the receptor or ion channel family in question. In addition, genes and proteins do not act in isolation; i.e., physiological function of a cell is the result of the combined interactive action of many gene products. Techniques are required that can simultaneously assess the expression of genes and their relationship with the function of ion channels in single cells.
