The brain never stops growing, scientists have found in landmark discovery that could help treat degenerative diseases.

Previously researchers believed that the brain did not grow any new cells after childhood, which is why it is so much harder for adults to pick up new skills or learn a foreign language.

More recent studies suggested that if specific zones of the brain were hyperstimulated then new cells could form, as was proven in London black cab drivers studying The Knowledge who were found to have an increased number of neurons in areas linked to mapping.

But a new study has found that new brain cells are actually forming all the time in their thousands, even when people are elderly.

It suggests that problems with mental ability and memory associated with old age are not down to a loss of neurons, but rather the failure of the cells to properly communicate with each other.