Computer Screen Snapshot (image) University of Iowa Share Print E-Mail Caption A computer screen shows the electrical activity of a specialized heart cell called a sinoatrial nodal cell. This type of cell can beat on its own without electrical stimulation, allowing scientist to see its activity when extracted. Information gleaned is contributing to understanding heart-pacing changes that occur during the body's "fight or flight" response to stress. Credit University of Iowa Usage Restrictions Image may only be used with appropriate caption or credit. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.