Alzheimer’s research findings could help patients remember loves ones

Scientists say breakdown of perineuronal nets around brain cells may explain why people with Alzheimer’s forget loved ones.

The findings could lead to new treatments using drugs already available for other conditions, researchers said.

A devastating consequence of the disease is that patients forget even close family and friends. Exactly which brain changes drive this remains debated.

Researchers at the University of Virginia in the US say the failure to recognise family, friends and carers is caused by the breakdown of protective structures called perineuronal nets that surround neurones.

They found that preventing the loss of these nets in laboratory mice prevented the loss of memories relating to previous social interactions.

“Finding a structural change that explains a specific memory loss in Alzheimer’s is very exciting,” said Harald Sontheimer, one of the study authors.

“It is a completely new target, and we already have suitable drug candidates in hand.”

Some 55 million people worldwide have Alzheimer’s, and this number is estimated to grow by 35 per cent over the next five years.

“In Alzheimer’s, people have trouble remembering their family and friends due to the loss of a memory known as social memory,” said Lata Chaunsali, another study author.

“We found that the net-like coating known as perineuronal nets protects these social memories.”

The study found that mice with faulty nerve nets lost their ability to remember other mice (their social memory), even when they could still form new memories of objects in their environment.

When these brain structures were kept safe early in life, the rodents with Alzheimer’s fared better at remembering their social interactions.

To protect the net structures, scientists used a class of drugs called MMP inhibitors, which are already being investigated for their potential to treat cancer and arthritis.

Since changes seen in mice align with those in human Alzheimer’s patients, researchers theorise that targeting the protective nets in people will offer similar benefits.

“Although we have drugs that can delay the loss of perineuronal nets, and thereby delay memory loss in disease,” Dr Sontheimer said.

“More research has to be done regarding safety and effectiveness of our approach before this can be considered in humans.”