Under a microscope, the picture of an Alzheimer’s brain shows areas where tangles are forming – tau (protein) collapses into twisted strands. The tracks can no longer stay straight; they fall apart and disintegrate. Nutrients and other essential supplies can no longer move through the cells, which eventually die.

‘The Christmas lights become grimy with plaque, their connections to each other are cut and they start to go out. Neurons are departing; memories are going.’

Sally Magnusson, Where memories go, 2014