Genetics and molecular biology of ionic channels in Drosophila

In this review the authors examine mutations that alter electrical excitability in the nervous system of the fruitfly, Drosophila melanogaster , and discuss how these mutations may be used to approach the molecular basis of ionic channel function. Electrical activity in the nervous system depends on the transient and selective movement of ions across nerve cell membranes. The falling phase is due to loss of Na super(+) permeability (inactivation) and increased permeability to K super(+). The key to action potential genesis lies in the nature of ionic permeability changes. Membrane macromolecules that act as ionic channels underlie these changes. In the low permeability condition, the channels are closed. Following an activation event, channels open into a conformation that allows ions to flow through.