Timing is everything: using fluidics to understand the role of temporal dynamics in cellular systems

In biology, it is not only the magnitude of a chemical stimulus that determines cellular response; it is becoming increasingly clear that the timing of the stimulus is vastly important as well. Currently there is a paucity of data regarding cell behavior under dynamic stimulation conditions that are representative of what occurs in vivo. This is, at least in part, attributed to the lack of appropriate tools for generating time-varying stimulatory signals in highly diverse patterns. Fluidics on the macro and micro scale has provided a practical platform for dynamically stimulating cells in a highly controllable manner at physiological and supra-physiological time scales (seconds to a few hours). These fluidic systems have contributed substantially to our understanding of how cells process and react to dynamic stimulatory environments; while these setups provide the means to analyze and manipulate cellular behavior in these types of environments on the single-cell level and on a high-throughput level, improvements can be made to these platforms to enhance their utility for high-impact biological investigations of temporal dynamics.