Fruit flies' memories reprogrammed with lasers
By Michael Conroy |16 October 2009 |Categories: Wired Science
Researchers at the University of Oxford have found a way rewrite the memories of fruit flies, causing them to respond to experiences they've never actually had.
Gero Miesenböck and his team began by introducing each fruit fly to a small chamber, into which they pumped two distinct odours which entered at either end of the container. Researchers would administer an electric shock when a fly strayed left or right into a particular odour stream, eventually causing the flies to learn to avoid that particular odour 30 per cent more often.
Having established a control group (and a collection of bewildered flies), the scientists then set about genetically engineering a separate group of fruit flies so that selected neurons would fire when shot at with a laser.
The team repeated the odorous test on the franken-flies, activating certain neurons in the flies' brains with a laser whenever they strayed into one of the two scents. They found that while some flies were completely impervious to the laser, those with twelve particular genetically altered neurons avoided the laser-related odour 28 per cent more often – nearly identical to the 30 per cent of flies in the control group.
The researchers hypothesise that by firing those 12 neurons they were able to create a feeling of fear that the flies learned to associate with the smell, as if they had previously had a negative experienced associated with it.
Essentially, they were creating false "memories" in the flies' brains. "These memories cause a lasting modification of the flies' behaviour," Miesenböck told New Scientist. "Stimulating just these neurons gives the flies a memory of an unpleasant event that never happened."
Taking these experiments to their natural conclusion, can we expect an army of laser-controlled, genetically modified humans? Miesenböck seems to think it's possible. "I would be surprised if the way humans learn from mistakes turned out to be fundamentally different from the way flies learn from mistakes."
Online editing by Holden Frith Fru