Researchers from the Cybernetic Intelligence Research Group at the University of Reading have developed a robot whose movements are controlled by neurons growing in a culture dish.
The robot’s “brain” consists of several hundred thousand neurons isolated from embryonic rat neocortex. The cortical tissue was first dissected out, then treated with enzymes which caused the cells to dissociate from one another. The resulting cell suspension was then added to a culture dish containing nutrients.
Rather than plating the cells onto a standard culture dish, the researchers instead grew them on one with a multi-electrode array embedded in its base. In the culture dish, the cells began to extend processes, then spontaneously formed synaptic connections and started to signal to one another. The dish contains 60 electrodes in its base and allows for bidirectional communication: the electrodes can not only detect the electrical signals produced by the neurons, but also generate their own signals and send them to the cells.
In this system, the neuronal culture “learns” how to control the robot. The spontaneous activity of the network directs the movements of the robot, which in turn feeds information about its environment back to the cells. This learning process was aided by the researchers, who added various chemicals to the cell culture to strengthen some connections and weaken others. By observing the behaviour of the cultured neurons, the researchers hope to gain insights into the cellular mechanisms of memory formation.
Multi-electrode arrays have been in use for several years now. In 2006, a team from the Neuroengineering Lab at Georgia Tech reported using electrode arrays to control the movements of virtual animals, and last year, Israeli researchers used a similar method to show that cultured neurons can store information. However, this is the first time that multi-electrode arrays have been used without a computer; in this case, the information is relayed between the neuronal culture and the robot by means of short-wave Bluetooth radio.
There’s more information about the research in the film clip below; see also the Combining Cognits blog, by Paul Baxter, who is a member of the Cybernetics Intelligence Research Group.