What controls intelligence? Researchers working on a ‘tag’ protein that tells other proteins where they should be are helping to address this question. Adding and removing tags allows developing brain cells (neurons) to respond quickly to their changing surroundings, while they form many connections that will convey electrical signals around the body. Healthy adult brain cells (shown in green, top left) have a single extended projection that makes long distance connections and carries signals away (stained turquoise, top centre and right) as well as many short extensions that carry signals back (stained red, top centre and right). Scientists showed that without a key protein which removes tags (bottom row) the turquoise projection is too short: it’s growth is insufficient to form long distance connections. This subtle change is enough to cause the brain to grow smooth, without the usual folds, and leads to intellectual disability.
Written by Julie Webb
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