A new study in mice has raised the tantalizing possibility that memory loss after a head injury could be reversible.
But you don’t need to experience a serious head injury to be at risk of complications. On average, college football players receive 21 head impacts per week – 41 for defensive ends – and scientists are working hard to try and understand what even these comparatively mild impacts could mean for their future.
A team of scientists at Georgetown University Medical Center had
“Most research in this area has been in human brains with chronic traumatic encephalopathy (CTE), which is a degenerative brain disease found in people with a history of repetitive head impact,” said senior investigator Dr Mark Burns in a
To that end, they took two groups of mice and exposed them to a situation that would provoke fear. Once they had learned the fear response and committed it to memory, one group of the mice was exposed to multiple, mild head impacts over the course of a week, mimicking a week in the life of the average college football player. The other mice acted as a control, receiving no head injuries.
After a week, the mice that had experienced repeated head trauma could no longer recall the fear they’d learned – but these were no ordinary mice. They’d been genetically modified so that the scientists could visualize the neurons involved in making the new memory in their brains – the “
Even after all those bumps on the head, the
“We are good at associating memories with places, and that’s because being in a place, or seeing a photo of a place, causes a reactivation of our memory engrams,” explained first author Dr Daniel P Chapman. “When the mice see the room where they first learned the memory, the control mice are able to activate their
Luckily for the mice, there’s a way for scientists to activate the engram cells manually, using
“We are currently studying a number of non-invasive techniques to try to communicate to the brain that it is no longer in danger, and to open a window of plasticity that can reset the brain to its former state,” said Burns.
While these findings won’t lead to a treatment in humans any time soon, they’re an important step forward in our understanding of how head trauma can lead to amnesia even in the short term, and of how it might be possible to
“Our research gives us hope that we can design treatments to return the head-impact brain to its normal condition and recover cognitive function in humans that have poor memory caused by repeated head impacts,” Burns said.
The study is published in