A microscope atop an animal's head, scientists have found, provides a better view of how the brain processes visual and other stimuli on the move.
The device contains a laser, which can scan the activity of neurons through a tiny hole in the skull, made under anaesthetic prior to the experiment, reports New Scientists.
The microscope was attached to freely moving rats looking at screens, and it produced images of brain cells that had been labelled with a fluorescent dye.
Previous methods had required restraining of animals and inserting of electrodes, but the new technique is much less invasive.
It reveals brain activity in animals that are moving and interacting with their environment in a more natural way.
The technique was developed at the Max Planck Institute for Biological Cybernetics in Tübingen, Germany.