Intravital imaging of cell signaling in mice

Cell signaling is mostly studied in in vitro 2D-cell culture models that lack the complex in vivo environment provided by neighboring cells, soluble secreted factors and non-cellular matrix components. Given that many environmental factors control cell signaling, it comes as no surprise that in vitro observations often poorly correlate with in vivo observations. Recent developments in intravital imaging techniques have made it possible to visualize and study cell signaling in individual cells within living animals. Here, we review intravital imaging techniques based on fluorescence microscopy and give examples of how these techniques are being used to study cell signaling.