Counting the Ways to Decode Dynamic Signals

The social amoeba Dictyostelium discoideum decodes an oscillatory signal to measure time. [Also see Research Article by Cai et al.] The role of biological signaling networks is to reliably transmit specific information about the extracellular environment to multiple intracellular downstream effectors, allowing the cell to adjust its physiological state to changing conditions. One mechanism that cells use to enhance the performance of signaling networks is the temporal modulation, or dynamics, of the transmitted signals (1–4). The key role that modulating temporal activity of the signal plays in information transmission makes signaling dynamics an attractive target for therapeutic approaches that interfere with the transmission of specific types of information through the network (5). The diversity of temporal modulation strategies seen in various signaling networks suggests that there is no single optimal strategy for making use of dynamic information. Therefore, to uncover the benefits of temporal modulation strategies, it is important to understand how the suitability of each type of signaling dynamics is matched to the nature of the particular information that is being transmitted. Some types of information are transmitted through frequency-modulated signals, whereas other types are transmitted through modulation of signal amplitude or duration. Work by Cai et al. (6) on page 1329 of this issue identifies how the social amoeba Dictyostelium discoideum decodes a temporally dynamic signal to coordinate its development in response to starvation.