Senarathna, J. et al. Nat. Commun. 10, 99 (2019).

Current miniature microscopes are limited to either fluorescence or hemodynamic imaging. Senarathna et al. developed a multi-contrast miniature microscope that is capable of imaging fluorescence signals, intrinsic optical signals, and laser speckle contrast at a resolution of 5 μm. Thus, it is possible to visualize neuronal activity, changes in cerebral blood volume, and cerebral blood flow with the same device. The microscope’s effective weight is 3 g, which is well tolerated by freely moving mice. The researchers applied the miniature microscope to visualize the responses to auditory stimuli in freely behaving mice. Furthermore, the researchers combined their multi-modal imaging with EEG recordings in mice awaking from anesthesia. Finally, they monitored the progression of a fluorescently labeled tumor and its effect on the vasculature. This work highlights the power of multi-modal imaging in freely behaving animals.