Figure 2 (IMAGE) Institute for Basic Science Caption (left) The circadian clock operates as a network where the master pacemaker and slave oscillator are organized in a hierarchical manner. Although they generate rhythms via an identical transcriptional-translational feedback loop (TTFL) of PER proteins, the generated PER rhythms are different between them. (right) By using a mathematical model describing the TTFL of the Drosophila circadian clock (top), we identified the differences between master and slave clock neurons (bottom). Credit Institute for Basic Science Usage Restrictions Attribution Required 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.