Aug 13, 2010 09:59 GMT  ·  By
A neuron was filled with a fluorescent dye so that the dendrites could be visualised. A laser was targeted to small spots on single dendrites to activate groups of inputs in different orders. The electrical response of the neuron was recorded and was foun
   A neuron was filled with a fluorescent dye so that the dendrites could be visualised. A laser was targeted to small spots on single dendrites to activate groups of inputs in different orders. The electrical response of the neuron was recorded and was foun

Single neurons and even single dendrites (the small receiving elements of neurons) can effectively identify and differentiate temporal sequences of incoming information, a new research carried out by UCL neuroscientists reveals.

Until now, the scientists' general point of view was that for processing information, the brain needs to group large numbers of neurons, but the study published in Science by researchers based at the Wolfson Institute for Biomedical Research at UCL, shows that the components of the brain are extremely powerful even individually.

Neuroscientists used a mouse model and studied neurons in areas of the brain which are responsible for processing sensory input from the face and the eyes.

They had a laser activating inputs on the dendrites in well-defined patterns and while recording the electrical response of the neurons they observed that each sequence produced a different response, even when it was delivered to a single dendrite.

“In everyday life, we constantly need to use information about sequences of events in order to understand the world around us, for example, language, a collection of different sequences of similar letters or sounds assembled into sentences, is only given meaning by the order in which these sounds or letters are assembled,” said first author Tiago Branco.

“The brain is remarkably good at processing sequences of information from the outside world, for example, modern computers will still struggle to decode a rapidly spoken sequence of words that a 5 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.”

Professor Michael Hausser, senior author of the study said about the experiment: “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.

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