Potassium channels are targets for several classes of drugs used to treat and control abnormal heart rhythms. Because many of these drugs are not specific or have unwanted side effects, there is great interest in developing better agents. In addition, several cardiac disorders are thought to involve changes in the production or properties of potassium channels.
Ion channels are proteins in cell membranes that open to allow ions to flow into or out of the cell.
Channels selective for sodium, potassium or calcium ions open when heart muscle is stimulated, like security gates that open when the right code is punched in. This redistribution of ions creates an electrical current that ultimately makes the muscle contract, enabling the heart to pump blood. During 10 years of electrophysiological experiments with heart muscle, Nerbonne has identified several types of potassium channels that differ in how quickly they open or how long they stay open to release ions. She also has determined how the various types of channels shape electrical activity and how they are affected by hormones or chemical messages from nerve cells. The new grant will allow her to explore the molecular basis for these physiological differences.