The drug, called IPW, blocks a gene known as TGF- that fuels the inflammation triggering blood protein albumin.
Prof Kaufer said: “We now have two biomarkers that tell you exactly where the blood-brain barrier is leaking, so you can select patients for treatment and make decisions about how long you give the drug.
“You can follow them, and when the blood-brain barrier is healed, you no longer need the drug.”
When they gave the drug to mice in doses that lowered the gene’s activity, their brains looked younger.
There was less inflammation and improved brain waves — as well as reduced seizure susceptibility. They also navigated a maze or learned a spatial task like a young mouse.
In an analysis of brain tissue from humans, Prof Kaufer found evidence of albumin in aged brains and increased neuro-inflammation and TGF- production.
Prof Friedman, of Ben-Gurion University of the Negev in Israel, developed a scanning technique called DCE (dynamic contrast-enhanced) – a special type of MRI. This detected more leakage in the blood-brain barrier of people with greater cognitive decline.