brain

As real as that daydream may seem, its path through your brain runs opposite reality.

Aiming to discern discrete neural circuits, researchers at the University of Wisconsin-Madison have tracked electrical activity in the brains of people who alternately imagined scenes or watched videos. "A really important problem in brain research is understanding how different parts of the brain are functionally connected. What areas are interacting? What is the direction of communication?" says Barry Van Veen, a UW-Madison professor of electrical and computer engineering. "We know that the brain does not function as a set of independent areas, but as a network of specialized areas that collaborate."

In 2005, Stanford scientist Karl Deisseroth discovered how to switch individual brain cells on and off by using light in a technique he dubbed 'optogenetics'.

Research teams around the world have since used this technique to study brain cells, heart cells, stem cells and others regulated by electrical signals.

However, light-sensitive proteins were efficient at switching cells on but proved less effective at turning them off.

Now, after almost a decade of research, scientists have been able to shut down the neurons as well as activate them.