Neurons self-organise to make brain chips

The technique could allow the development of sophisticated biological sensors that use functioning brain cells, the researchers say. This type of device would identify a compound - a deadly nerve agent or poison, for example - by measuring its effect on a functioning network of neurons.

Axons and dendrites carry electrical signals between neurons. The electrical activity of the neural network can easily be measured because carbon nanotubes conduct electricity and so can function as electrodes.

The process makes it possible to create more uniform neural networks, Hanein says. In experiments they last longer than other artificial networks, surviving for up to 11 weeks.

Smith says finding ways to connect to individual neurons in similar arrangements would be even more useful. "That's the holy grail," he told New Scientist. "The best labs can only really put an electrode near a neuron of interest. Finding a way to connect directly and non-invasively is much harder."