Anyone who has had a bad night knows that they can feel ‘foggy’ the next day. This fogginess may extend to our memory: remembering where we went, who we met, or what happened during the encounter. Neuroscientist Robbert Havekes from the University of Groningen studies memory loss due to sleep deprivation. In a study published in the journal Science Advances on 10 June, Havekes and lab member and first author Adithya Sarma show that sleep deprivation makes mice forget social encounters. However, they found that the social memories are not gone, the mice just can’t seem to recall them.
Havekes and his team studied mice who had social encounters with several other mice, each time in the same environment. Under normal circumstances, they would recognize the other mice when encountering them again. However, when they were sleep deprived after the first encounter, they did not recognize the mice at a later moment. But when they were given the clinically approved asthma drug roflumilast before that second encounter, they did recognize their fellow mice.
This suggests that the drug gives them access to those memories that were otherwise not accessible. In previous work, Havekes has found the same effect for spatial memories: sleep deprivation made the mice forget spatial information about a maze they had visited and roflumilast restored access to those memories.
The team found further evidence using optogenetics, a technique that allows specific groups of brain cells (memory engrams) to be activated with light. By reactivating brain cells involved in the original social experience, they were able to restore access to social memories disrupted by sleep deprivation. The restored access persisted for several days, suggesting that the memories themselves had remained stored in the brain.
‘We knew that spatial memory was vulnerable to sleep deprivation, with the hippocampus, a part of the brain that’s responsible for your memory and learning, playing a major role,’ explains Havekes. ‘What we didn’t know is that sleep deprivation also severely impairs the retrieval of memories of social interactions involving the same brain region. There is a logic to this, says Sarma: ‘In everyday life, social memories rarely occur in isolation. We often meet multiple individuals in the same place and must keep those experiences separate.’ Havekes: ‘We saw that sleep deprivation affects both types of memories through a similar process, which can be countered by roflumilast.’
The next challenge is to determine the exact mechanism underlying this process. Havekes: ‘If we can understand the underlying mechanism, we may develop novel ways to truly and persistently restore the recall of individual social experiences, but also target other forms of amnesia.’ This might have implications for forms of retrograde amnesia, such as in Alzheimer’s disease, but also for people who regularly lose sleep, such as shift workers, healthcare workers, students, or parents of young children.
Reference: Adithya Sarma et al., Sleep deprivation impairs retrieval of long-term social memories . Science Advances, 10 juni 2026
Science Advances
Experimental study
Animals
Restoring access to long-term social recognition memories disrupted by sleep deprivation
10-Jun-2026
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