AEUR” is an HIV drug also known as maraviroc. It may also have a surprising use.
A team from Nature reports that the medication restores a type memory that allows us link events, such as weddings, with people we see there.
Maraviroc was able to improve this type of memory in mice. However, the drug also acts on a brain system found in humans. It plays a role in many problems in the brain and nervous systems.
“You might have an impact in Alzheimer’s, stroke, Parkinson’s, and also spinal cord injuries,” Dr. S. Thomas Carmichael of the University of California, Los Angeles chair of neurology, said.
Relational memory is the ability to link memories that happen at the same time. This ability declines with age and can be severely impaired by Alzheimer’s disease.
Alcino Silva, a UCLA researcher and director of The Integrative Center for Learning & Memory, said that problems with relational memory may occur in people who are able to form new memories easily.
“You may learn something about it, but you don’t remember where it was heard.” Silva states that you can’t recall who told it to you. These incidents occur more frequently as we age, especially in middle age.
Silva says scientists have known for some time about relational memory. “How the brain does this is what we don’t know.”
Silva’s laboratory began to study a molecule called CCR5.
CCR5 plays a crucial role in the immune system. CCR5 is a brain protein that controls the process of separating old memories from new ones. This separation would make it impossible to tell whether someone we met at the wedding last week or at a conference many decades ago.
Silva doubted the CCR5 molecule could be responsible for why mice and humans develop memory problems as they age.
He says, “But we checked and voila!”
It was found that CCR5 levels increase with age and “turn off” the ability of linking memories.
Silva’s lab tested this idea on mice with a disabled CCR5.
These mice were able to link memories that had been created a week apart. Typical mice could only link memories that had been made within a few hours.
The team took normal, middle-aged mice and infused maraviroc into their hippocamus, which is an important area for memory.
Silva said, “This drug gave me the same thing.” It restores memory linking.
Carmichael believes that the results are promising for people aged over 60 and stroke patients.
Silva and Carmichael co-authored a 2019 paper that showed CCR5 levels rise after strokes.
Carmichael states that in the short-term, this CCR5 surge activates systems that help brain cell survive. “The problem with those systems is that they remain active and limit the brain’s ability to recover.”
Brain cells must form new links to repair long-term stroke damage. This process is similar to the one that connected certain memories. CCR5 stops that.
Silva and Carmichael gave maraviroc to mice with brain injuries or strokes. They recovered quicker than the other mice, it was evident.
They then studied stroke patients who had low levels of CCR5. This resulted in a faster recovery.
Carmichael currently participates in a study to determine if maraviroc can be used to help stroke victims.
