14 DAY TRIAL // People usually take many things for granted, including the ability to always appear in motion in a static world. The human brain is able to receive constant updates from all its sensors – eyes, ears, skin, nose and so on – and then update our position in real-time. When this happens cursively, we understand it as being in motion, as opposed to static landmarks. Therefore, it could be hypothesized that our understanding of the world depends on moving freely through it, as well as on exploring it. So far, scientists seeking to learn the mechanisms involved in this process have been unable to understand them.
One of the main reasons for this inability is the fact that imaging techniques usually use large equipment that is static. Now, for the first time ever, experts at the Max Planck Institute for Biological Cybernetics, in Tubingen, Germany, managed to overcome this obstacle by creating a small, light-weight laser-scanning microscope. The instrument is so small that it can be used on the brains of lab rats while the rodents move freely. The achievement could bring about a wealth of knowledge about how the brain functions, in an area of research that has remained relatively unexplored over the years.
The investigators gave the rats a substance that made their neurons fluorescent, which, in turn, allowed the laser-scanning microscope to pick up their signatures. Unlike any other study before this, the rats were awake and moving freely in the lab environment, while the researchers tracked their position in space live. Another innovation that was applied was the fact that no electrodes were needed for the new instrument to work. Therefore, the observation method is non-intrusive and it works by scanning the nerve cells immediately below the surface of the cortex.
“We need to let the animal behave as naturally as possible if we want to understand how its brain operates during interaction with complex environments. The new technology is a major milestone on the way to helping us understand how perception and attention work,” Max Planck expert Jason Kerr, the lead author of the new study, explains. He adds that the new microscope allows experts to observe the formation of internal representation of the outside world in real-time, by collecting readings from a large number of cells at the same time.