High-speed, miniaturized fluorescence microscopy in freely moving mice

Abstract
A miniature epifluorescence microscope that can be carried by a freely-moving adult mouse allows cellular-level imaging of neuronal spiking or measurement of microcirculation during normal behavioral activities. A central goal in biomedicine is to explain organismic behavior in terms of causal cellular processes. However, concurrent observation of mammalian behavior and underlying cellular dynamics has been a longstanding challenge. We describe a miniaturized (1.1 g mass) epifluorescence microscope for cellular-level brain imaging in freely moving mice, and its application to imaging microcirculation and neuronal Ca2+ dynamics.