Mini microscopes see inside the brains of mice

Mini microscopes embedded into the brains of genetically engineered mice are providing researchers a window onto the inner workings of the mammalian mind.

The tool provides an unprecedentedly wide field of view on the mouse brain – in one mouse, for example, the team recorded the firing of more than 1,000 individual neurons – and it can record for weeks on end, allowing scientists to study how brain activity evolves over time.