Organic robot mixes rat brain with silicon

A research team at the Georgia Institute of Technology has created a new kind of robot, the Hybrot, which lead researcher Professor Steve Potter says has great implications for understanding the human brain.

The Hybrot looks like many other experimental and kit robots -- an exposed circuit board above a chassis containing motors and batteries. But one of the chips sits on top of a small metal cylinder, a patented sealed incubator system that contains the control circuits of the device: live rat brain cells. The system will keep the neurons alive for up to two years, while other circuits connect them to the electronics of the robot.

"We call it the 'Hybrot' because it is a hybrid of living and robotic components," said Potter in a statement. "We hope to learn how living neural networks may be applied to the artificial computing systems of tomorrow. We also hope that our findings may help cases in which learning, memory, and information processing go awry in humans."

The incubator contains a few thousand living neurons cultured from rat cortex and placed on a special glass dish equipped with an array of 60 micro-electrodes. The neural activity recorded by the electrodes is transmitted to the robot, which serves as a body for the cultured networks. It moves under the command of neural activity, relaying information back from the robot's sensors to the cultured net as electrical stimulation.

As the neurons form a network and react to the external stimuli, the research team can make observations of the signalling patterns, and changes in the way the cells hook up and configure themselves. High speed cameras and voltage-sensitive dyes, in conjunction with laser-scanning microscopes, return information that the team hope will show evidence for growth and learning patterns in biological systems.

"Learning is often defined as a lasting change in behaviour, resulting from experience," said Potter. "In order for a cultured network to learn, it must be able to behave. By using multi-electrode arrays as a two-way interface to cultured mammalian cortical networks, we have given these networks an artificial body with which to behave."

UK readers may be interested to note that the combination of a biological brain in a mechanical wheeled transporter has been seen before in this country, in the form of Dr Who's most implacable enemies, the Daleks.

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