Oct. 22 - Researchers at Harvard University have managed to take control of a roundworm's brain. After genetically engineering the worm to make its neurons sensitive to light, the scientists found they could control its movements through stimuli projected into its brain. Ben Gruber reports.
This microscopic roundworm is chasing food…food that doesn't exist - scientists have tricked the worm, and they did it by taking over its tiny brain. Sharad Ramanathan and his team want to better understand how biological networks operate. They have spent the past four years studying the 300 neurons that make up the worm's brain and finding ways to track and control each one. They genetically engineered the worm's neurons to emit fluorescent light so they could track them and to become light sensitive, so they could turn each one on or off with laser pulses. (SOUNDBITE) (English) SHARAD RAMANATHAN, ASSISTANT PROFESSOR OF MOLECULAR BIOLOGY, HARVARD UNIVERSITY, SAYING: "And suddenly by controlling that neuron we could control turning, left or right. Going forward or backward. And this neuron received lots of sensory information, so just by controlling this neuron we could figure out how this animal should move and remote control it basically. And then the point is can we make it think there is food and just by controlling the activity of this neuron we could make it think there was food and it would make a beeline to where the food was suppose to be but there was no food. We were playing with the brain to make it think that there was food." Researcher Askin Kocabas says the hard part was de-vel-op-ing the system to track and tar-get individual neurons in the worm's brain while it was in motion. (SOUNDBITE) (English) ASKIN KOCABAS, RESEARCHER, HARVARD UNIVERSITY, SAYING: "We are using complex image processing algorithms here and then we can acquire the image and then we can process the image and then we can identify the neurons position and then we can specifically focus light into specific neurons." And even with the tiny worm squirming away they managed to accurately fire lasers at its neurons 50 times per second. The system uses a movable table which keeps the worms centered beneath an ultra fast camera. Once they have the real time image - they can target and shoot neurons - giving them overall control of the worm's brain. (SOUNDBITE) (English) SHARAD RAMANATHAN, ASSISTANT PROFESSOR OF MOLECULAR BIOLOGY, HARVARD UNIVERSITY, SAYING: "The question further up is can we start doing such things with higher organisms like zebrafish where the brain is infinitely more complex or so it seems and start asking similar questions in the hope of understanding how biological networks are designed." The team believes those "higher organisms" might be the zebra fish, whose brains are more complex than the roundworm. But Ramanathan says that is still years away. He says tracking and targeting a microscopic worm is one thing - but keeping up with a moving fish is still the stuff of science fiction.