Neuroscientists at University College London (UCL) have used laser beams to “switch on” neurons in mice, providing new insight into the hidden workings of memory and showing how memories underpin the brain’s inner GPS system.

The study, published in the journal Cell, explains how researchers harnessed an ‘all-optical’ approach using twin lasers to simultaneously read and write the activity of ‘place cells’ (a type of neuron) in mice, as they navigated a virtual reality environment.

Remarkably, by stimulating the place cells, scientists were able to reactivate (or retrieve) the memory of a location where the mice obtained a reward, which in turn “mentally teleported” the mice, causing them to act as if they were in the rewarded place.