Scientists have used living human brain tissue to mimic the early stages of Alzheimer’s disease, the most common form of dementia, in a breakthrough that will accelerate the hunt for a cure, reports The Guardian.

In a world first, a British team successfully exposed healthy brain tissue from living NHS patients to a toxic form of a protein linked to Alzheimer’s—taken from patients who died from the disease—to show how it damages connections between brain cells in real time.

The groundbreaking move offered a rare and powerful opportunity to see dementia developing in human brain cells. Experts said the new way of studying the disease could make it easier to test new drugs and boost the chances of finding ones that work.

Dementia presents a big threat to health and social care systems across the world. The number of people affected is forecast to triple to nearly 153 million by 2050, which underlines why finding new ways to study the disease and speed up the search for treatments is a health priority.

In the study, scientists and neurosurgeons in Edinburgh teamed up to show for the first time how a toxic form of a protein linked to Alzheimer’s, amyloid beta, can stick to and destroy vital connections between brain cells.

Unlike when exposed to a normal form of the protein, the brain did not attempt to repair damage caused by the toxic form of amyloid beta, the scientists found.

Even small changes in natural levels of amyloid beta—increasing or decreasing—were enough to disrupt brain cells. This suggests that the brain requires a finely tuned sweet spot of the protein to function properly, the scientists said.

The breakthrough will enable scientists to home in on drugs with the best chance of preventing the loss of synapses—connections that allow the flow of messages between brain cells and are vital to healthy brain function. Alzheimer’s attacks synapses, and their loss strongly predicts reduced memory and thinking abilities.