In vivo imaging of the mouse lung ― a very challenging organ to image ― is reported this week in Nature Methods. Being able to image the lung, and possibly other organs, with a minimum disruption of normal function, should enable scientists to look deeper into many aspects of physiology and disease.
Imaging tissues or organs is ideally done within the living organism and as noninvasively as possible. But there are many challenges. Light is absorbed and scattered as it passes through tissue, degrading image quality. Furthermore, even anesthetized animals have a pulse and respiratory movements, complicating the imaging of dynamic processes. Many of these problems are exacerbated in the lung.
Yet the lung is the site of several important functions. It is a major location at which the internal milieu of the body encounters the environment, by way of inhaled air and its attendant toxins and pathogens. Both for respiration and immune function, the lung vasculature is in constant and relatively intimate contact with inhaled air.
Matthew Krummel and colleagues combine a series of classical and cutting-edge techniques to image the lung in the living mouse, and to do so without disrupting its normal physiology. Using two photon microscopy, they watch immune cells moving within the lung capillaries.