Heart nerves (IMAGE) Johns Hopkins Medicine Caption This image illustrates the novel role of heart nerves in postnatal hearts where sympathetic neurons influence clock genes to regulate cell cycle progression of heart muscle cells. Credit Photo courtesy of Emmanouil Tampakakis Usage Restrictions none License Original content 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.