The results will now give scientists an unprecedented glimpse at how these harmful deposits function at a molecular level, and could lead to a number of new treatments to prevent them from forming – and in doing so, help to combat Alzheimer's and dementia.

"This is a tremendous step forward," says one of the team, Bernardino Ghetti from Indiana University.

"It's clear that tau is extremely important to the progression of Alzheimer's disease and certain forms of dementia. In terms of designing therapeutic agents, the possibilities are now enormous."

In the new study, researchers led by the MRC Laboratory of Molecular Biology (LMB) in the UK extracted tau protein filaments from the brain of a deceased patient with a confirmed diagnosis of Alzheimer's disease, and imaged them using a technique called called cryo-electron microscopy (cryo-EM).