De Groot, A. et al. Elife 9, e49987 (2020).
Miniature microscopes are available in a variety of versions, both commercially and custom-built. De Groot et al. add an especially lightweight and versatile option. With a weight of just 1.6 grams, the so-called NINscope has a small footprint, comes with an on-board accelerometer and can drive an LED for optogenetic stimulation. Despite the trimmed-down design, the scope’s high image quality allowed extraction of neuronal activity from GCaMP6f-expressing neurons in the cortex and cerebellum. During imaging, mouse behavior can be monitored with the accelerometer. The small footprint and low weight of the NINscope even allowed the placement of two miniscopes on one mouse without impairment of behavior. Therefore, the researchers could conduct dual-region imaging in freely behaving mice, which they demonstrated for the cerebellum and the cortex or for both hemispheres of the visual cortex.