Ratty the robot

US researchers have developed a small robot whose movements are controlled by a network of cultured neuron cells from a rat.

Georgia Tech Professor Steve Potter and his research team in the Laboratory for Neuroengineering at the Georgia Institute of Technology have developed a small robot whose movements are controlled by a network of cultured neuron cells from a rat.

‘We call it the ‘Hybrot’ because it is a hybrid of living and robotic components,’ Professor Potter said. ‘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.’

To make the robot, a droplet containing a few thousand living neurons from rat cortex is placed on a special glass petri dish instrumented with an array of 60 micro-electrodes. The neurons are kept alive in an incubator for up to two years using a new sealed-dish culture system that Potter developed and patented. The neural activity recorded by the electrodes is transmitted to the robot which serves as the body of the cultured networks. It moves under the command of neural activity that is being transmitted to it, and information from the robot’s sensors is sent back to the cultured net in the form of electrical stimuli.

Central to the experiments is Potter’s belief that over time, the team will be able to establish a living network system that learns like the human brain.

So far, the researchers have made detailed observations of the neural signalling patterns, and documented changes in the morphology and connectivity of the cells and networks by using high-speed cameras and voltage-sensitive dyes, in conjunction with 2-photon laser-scanning microscopy. They are also looking for evidence that the networks are growing and learning over time.

‘Learning is often defined as a lasting change in behaviour, resulting from experience,’ Potter said. ‘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.’

Potter’s group hopes the research will lead to advanced computer systems that could some day assist in situations where humans have lost motor control, memory or information processing abilities. The neural interfacing techniques they are developing could be used with prosthetic limbs directly controlled by the brain.