Nobel laureate Francis Crick - one of the discoverers of the DNA spiral - presented a literally brilliant idea during a lecture exactly twenty years ago. He suggested that researchers should invest in re-altering different types of neurons in the brain of live laboratory animals so that the cells can be controlled by light.

Then it was science fiction. Today, the method is found in hundreds of laboratories around the world, including Sweden.

Mice were remotely controlled

American psychiatrist Karl Deisseroth succeeded in introducing a gene from photosensitive algae into nerve cells in mice. Using laser rays via a fiber cable into his head, he was then able to control selected nerve cells - and thus the behavior of the mice.

The method is called optogenetics and has shed new light on what happens in the brains of laboratory animals when they show signs of being scared, angry, sexually attracted and much more.

If today's award goes to the so-called optogenetics, Karl Deisseroth becomes one of the recipients. Other names include Austrian Gero Miesenböck (who has been researching at Umeå University for a few months) and German Ernst Bamberg.

The washing machine starts during sleep

A possible prize winner in a completely different area is the Danish Maiken Nedergaard. She has discovered that the brain gets rid of harmful slag products with the help of something she calls the lymphatic system - a kind of built-in washing machine that starts when you fall asleep.

The discovery is important because harmful proteins accumulate in the brain of people with neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's.

Mini-brains are grown in test tubes

One concern for neuroscientists is that they rarely access brain tissue from living humans. It is relatively easy to take samples from the skin, muscles and many other tissues. Drilling holes in someone's skull to take a sample from the brain is usually impossible for ethical reasons.

But research on stem cells has made it possible to use human stem cells to grow "mini brains" in test tubes. These so-called organoids provide new opportunities to test drugs for brain disorders.

The experiments do not require laboratory animals. However, they have led to a serious discussion about whether the cultured mini-brains can be so advanced that they gain consciousness. In that case, some believe, researchers must take into account their possible suffering. A Nobel Prize in this field could go to the Dutchman Hans Clevers.

Today at 11.30 we will know who will receive the prize.