Memories “lost” due to sleep deprivation may still be there and a drug could help recall them, according to a new study in mice. The human-approved asthma drug roflumilast was able to help mice recall memories they were previously unable to grasp after sleep deprivation, which could be of great help to children. people with amnesia and other sleep-related disorders.
We’ve all been there – the exam is approaching and you’re woefully unprepared, and now you have to make the fateful decision between cramming through the night and rocking with your eyes half closed or getting a good night’s sleep and hoping the revision you made is enough. I personally chose a hard version of the two, in which I found myself sleep deprived but unable to remember the information I had crammed in the night before.
Previously, scientists simply assumed that these memories were lost, with sleep deprivation preventing the brain from memorizing the information. However, new research suggests they may still exist in the brain, but something is stopping us from accessing them.
“Sleep deprivation undermines memory processes, but every student knows that an answer that escaped them during the exam can appear hours later. In this case, the information was actually stored in the brain, but difficult recover,” study author and University of Groningen neuroscientist Robbert Havekes said in a statement.
To understand whether the problem lies in creating or recalling memories created during episodes of sleep deprivation, scientists turned to optogenetics. By causing the production of a light-sensitive protein in specific neurons that are activated during learning, the researchers were then able to use light to see exactly what was going on in the cells.
The mice were given a task in which they had to learn the individual locations of the objects and then remember their location after being moved a few days later. In the sleep-deprived mice, they failed to remember the locations, but when the researchers activated neurons involved in memory recall, the mice were then able to identify the locations again.
“However, when we reintroduced them to the task after reactivating the hippocampal neurons that initially stored this information with light, they were able to remember the original locations,” Havekes continued.
“This shows that information was stored in the hippocampus during sleep deprivation, but could not be retrieved without the stimulation.”
The researchers then gave the mice the drug roflumilast, which is approved for use in humans, in an attempt to mimic the activation of memory neurons. These mice recalled object locations, just as before, suggesting a possible avenue of use for recovering “lost” memories with this drug. Further trials will be needed, including possible human trials, but this highlights the possibility that memories are actually created during periods of sleep deprivation, although they are inaccessible for some reason.
“It might be possible to boost memory accessibility in people with age-induced memory problems or early-stage Alzheimer’s disease with roflumilast,” Havekes said.
“And perhaps we could reactivate specific memories to make them permanently retrievable again, as we have successfully done in mice.”
The research was published in Current Biology.