By Robin Lettice

Posted in Science, 7th December 2004 16:01 GMT

Florida scientists have grown a brain in a petri dish and taught it to fly a fighter plane.

Scientists at the university of Florida taught the 'brain', which was grown from 25,000 neural cells extracted from a rat embryo, to pilot an F-22 jet simulator. It was taught to control the flight path, even in mock hurricane-strength winds.

"When we first hooked them up, the plane 'crashed' all the time," Dr Thomas DeMarse, an assistant professor of biomedical engineering at the University of Florida, said. "But over time, the neural network slowly adapts as the brain learns to control the pitch and roll of the aircraft. After a while, it produces a nice straight and level trajectory."

The brain-in-a-dish was DeMarse' idea. To produce it, 25,000 rat neurones were suspended in a specialised liquid to keep them alive and then laid across a grid of 60 electrodes in a small glass dish.

The cells at first looked like grains of sand under the microscope, but soon began to connect to form what scientists call a "live computation device" (a brain). Electrodes monitor and stimulate neural activity in this network, allowing researchers to study how the brain processes and transfers information.

The scientists hope that their research will lead to hybrid computers with organic components, allowing more flexible and varied means of solving problems.

One potential application is to install living computers in unmanned aircraft for missions too dangerous for humans. It is also hoped that further advances will help in the search for cures for conditions such as epilepsy, The Age reports (http://www.theage.com.au/articles/2004/12/06/1102182227308.html).

"The algorithms that living computers use are also extremely fault-tolerant," Dr DeMarse said. "A few neurons die off every day in humans without any noticeable drop in performance, and yet if the same were to happen in a traditional silicon-based computer the results would be catastrophic."

The US National Science Foundation has awarded the team a $500,000 grant to produce a mathematical model of how the neurons compute. ®