Scientists using living human brain tissue have shown for the first time how a toxic form of a protein linked to Alzheimer’s can stick to and damage the connections between brain cells.

Small pieces of healthy human brain tissue —collected during routine neurosurgery operations—were exposed to the protein, known as amyloid beta.

Unlike when subjected to a normal form of the protein, the brain tissue did not attempt to repair damage caused by the toxic form of amyloid beta, experts say.