UK study shows single neurons can think for themselves

British researchers have shown that individual neurons are capable of processing far more complex information than traditionally thought.

Published today in the journal Science, a study by researchers at the Wolfson Institute for Biomedical Research at UCL (University College London) demonstrated that lone neurons, as well as the single dendrites which act as their antennae, are able to distinguish clearly between different sequences of incoming information.

"The brain is remarkably good at processing sequences of information from the outside world," explains Dr Tiago Branco, first author of the study. "For example, modern computers will still struggle to decode a rapidly spoken sequence of words that a five year-old child will have no trouble understanding.

"How the brain does so well at distinguishing one sequence of events from another is not well understood but, until now, the general belief has been that this job is done by large numbers of neurons working in concert with each other."

The researchers studied areas in the brains of mice responsible for processing sensory input from the eyes and the face. Seeking to observe the response of these neurons to inputs they applied a laser to activate dendrites in specific patterns and then recorded the electrical response of the neurons. The results were surprising.

The researchers found that each sequence produced a different response, even when it was delivered to a single dendrite. Applying theoretical modelling, they showed that it was highly likely that single neurons and dendrites would be able to distinguish two different sequences.

"This research indicates that single neurons are reliable decoders of temporal sequences of inputs, and that they can play a significant role in sorting and interpreting the enormous barrage of inputs received by the brain,” senior study author Professor Michael Hausser said.

"This new property of neurons and dendrites adds an important new element to the 'toolkit' for computation in the brain. This feature is likely to be widespread across many brain areas and indeed many different animal species, including humans."

UK’s Wellcome Trust recently provided Professor Hausser with further funding to study the affect that single neurons have on neighbouring networks of neurons. This work is expected to shine new light on the relationship between neuron activity and perception, decision-making and behaviour.