NERVE CELLS MAY HOLD THEIR FIRE to allow their neighbors to send electrical signals, researchers have proposed, potentially explaining how interconnected networks of nerve cells send information with high fidelity, and providing insights into how to design better signal-processing devices for electronic equipment such as CD players. At a cocktail party, many people talk simultaneously, and one is able to hear several nearby conversations at once. In a conference call, on the other hand, people generally take turns to speak. Researchers (Doug Mar, Boston University, 617-353-5463) have proposed that an interconnected network of nerve cells is similar to a conference call: when a nerve cell fires, its neighbors are inhibited and do not fire until it is done. One consequence is that the nerve cells fire in rapid succession, permitting the network to transmit signals at higher frequencies. Moreover, the pattern of random firings of nerve cells, corresponding to noise, is smoothed out, enabling the cells to convey information with higher fidelity. Finding direct evidence for these phenomena in biological systems will be challenging, because it is currently difficult to measure accurately the firing patterns of several interconnected neurons simultaneously. In the meantime, the researchers are working with Analog Devices, Corp. in Massachusetts to apply the lessons from the theory to creating biologically inspired networks of interconnected electric circuits with improved characteristics, such as an extended range of operating frequencies. (Mar et al., Proceedings of the National Academy of Sciences, 31 August.)