The majority of our life is spent moving around a static world and we generate our impression of the world using visual and other senses simultaneously. It is the ability to freely explore our environment that is essential for the view we form of our local surroundings. When we walk down the street and enter a shop to buy fruit, the street, shop and fruit are not moving, we are. What our brain is probably doing is constantly updating our position based on the information received from our sensory inputs such as eyes, ears, skin as well as our motor and vestibular systems, all in real time. The problem for researchers trying to understand how this occurs has always been how to record meaningful signals from the brain cells that do the calculations while we are in motion. To get around this problem researchers at the Max Planck Institute for Biological Cybernetics in Tübingen have developed a way of actually watching the activity of many brain cells simultaneously in an animal that is free to move around the environment. By developing a small, light-weight laser-scanning microscope, researchers were able to, for the first time, image activity from fluorescent neurons in animals that were awake and moving around, while tracking the exact position of the animal in space. The microscope uses a high-powered pulsing laser and fiber optics to scan cells below the surface of the brain, eliminating the need to insert electrodes, which are traditionally used. Because of this, the microscope is non-invasive to the brain tissue.
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