Researchers at the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine), have found that caffeine may help restore a specific form of memory impaired by sleep deprivation.
The study provides new evidence that caffeine acts on a defined brain pathway associated with social memory, rather than only improving alertness.
Published in Neuropsychopharmacology, the research suggests that caffeine may have a more targeted role in supporting cognitive function, particularly in conditions where sleep loss disrupts memory-related brain circuits.
The study was led by Associate Professor Sreedharan Sajikumar from the Department of Physiology and the Healthy Longevity Translational Research Program at NUS Medicine, together with first author Dr. Lik-Wei Wong.
Researchers focused on the hippocampal CA2 region, a specialized area of the brain involved in forming social memory, which enables individuals to recognize and distinguish people they have previously encountered.
The hippocampus is central to learning and memory, while the CA2 region plays a distinct role in social recognition and receives signals linked to sleep and wake regulation.
Sleep deprivation disrupts neural communication
To examine the impact of sleep loss, laboratory animals were subjected to five hours of sleep deprivation. The researchers then studied changes in brain activity using electrophysiological recordings of hippocampal tissue.
Findings showed that sleep deprivation disrupted synaptic plasticity in the CA2 region, weakening communication between neurons and reducing the brain’s ability to strengthen important neural connections. These changes were directly linked to reduced performance in social recognition memory tasks.
Caffeine restores synaptic function
Caffeine was administered in drinking water over a seven-day period following sleep deprivation. The compound, known to block adenosine receptors that regulate sleep pressure, was found to restore synaptic communication in the CA2 region.
The study showed that caffeine normalized synaptic plasticity and reversed deficits in social memory caused by sleep loss. Importantly, its effects were selective, acting on disrupted neural pathways rather than broadly stimulating brain activity.
Control groups that did not experience sleep deprivation showed no signs of excessive neural activation despite caffeine exposure, indicating a regulated and targeted mechanism of action.
Implications for cognitive health
Commenting on the findings, Dr. Lik-Wei Wong said that sleep deprivation affects more than alertness, as it selectively disrupts key memory circuits.
Caffeine was able to reverse these disruptions at both molecular and behavioral levels, suggesting broader cognitive effects beyond wakefulness.
Associate Professor Sajikumar said the CA2 region serves as a critical link between sleep regulation and social memory. He added that the study improves understanding of the biological mechanisms underlying sleep-related cognitive decline and could support future research into preserving memory function.
The researchers highlighted the importance of adequate sleep in maintaining healthy brain function and memory performance.
The findings also suggest potential pathways for targeted interventions in sleep-related cognitive impairment.
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