“Taking caffeine before a period of sleep deprivation can fully restore social memory function that would otherwise be impaired.”

Sleep deprivation (SD) is a critical risk factor for cognitive decline and is closely linked to psychiatric disorders. The hippocampal CA2 region is critically involved in encoding social memory and regulating emotional behavior, and it has been implicated in various neuropsychiatric conditions. ... Electrophysiological recordings revealed that SD markedly impaired long-term potentiation (LTP) in CA2 and disrupted social recognition memory, as evidenced by failure to distinguish novel from familiar conspecifics. These deficits were accompanied by upregulation of adenosine A1 receptors and PDE4A5, along with reduced expression of plasticity-related proteins including PKMζ, ERK, and BDNF. Moreover, caffeine-induced synaptic potentiation was diminished in SD mice, whereas caffeine supplementation reversed both synaptic and behavioral impairments. Together, these findings demonstrate that SD compromises CA2-dependent plasticity and social cognition through adenosine receptor signaling and identify CA2 as a vulnerable, therapeutically relevant region. Targeting adenosine pathways may represent a novel strategy to mitigate sleep loss-related cognitive dysfunction in neuropsychiatric disorders.

Researchers at the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine), have demonstrated that caffeine can restore social memory impaired by sleep deprivation by targeting a defined brain pathway. The study findings revealed that sleep deprivation disrupted the maintenance of synaptic plasticity, weakening communication between neurons in the hippocampal CA2 region of the brain, and taking caffeine prior to sleep deprivation led to a recovery of synaptic communication in the CA2 region and plasticity returned to normal levels. Specifically, social memory deficits were reversed and the effects of caffeine were pathway specific, selectively restoring the disrupted brain circuit rather than globally increasing neural activity.

Researchers at the Yong Loo Lin School of Medicine, National University of Singapore (NUS Medicine), have demonstrated that caffeine can restore social memory impaired by sleep deprivation by targeting a defined brain pathway. Specifically, social memory deficits were reversed and the effects of caffeine were pathway specific, selectively restoring the disrupted brain circuit rather than globally increasing neural activity.

Chronic administration of caffeine prevented impairment of spatial learning, short-term memory and E-LTP of area CA1 in 24-h sleep-deprived rats. The results suggest that long-term use of a low dose of caffeine prevents impairment of short-term memory and E-LTP in acutely sleep-deprived rats.

During sleep deprivation in a laboratory study, acute caffeine administration (200 to 600 mg per day) helped to reduce sleepiness and EEG theta activity during wakefulness and to protect cognitive function by preventing a decrease in sustained attention. However, acute caffeine intake in response to insufficient sleep can interfere with the onset and maintenance of the subsequent restorative sleep necessary for the recovery of physical and cognitive performance.

A reduction in sleep does not occur independently of the effects on memory, attention, alertness, judgment, decision-making, and overall cognitive abilities in the brain, resulting in decreased function and impaired cognitive performance. Sleep deprivation appears to disrupt memory consolidation in the hippocampus through long-term potentiation (LTP).

Inadequate sleep negatively affects all three learning processes. Acquisition and recall suffer in the most recognizable way. The less obvious—but possibly more profound—impact of sleep deprivation on learning is the effect that many sleep researchers think it has on memory consolidation.

“We found that sleep deprivation impaired performance on both types of tasks and that having caffeine helped people successfully achieve the easier task. However, it had little effect on performance on the placekeeping task for most participants,” Fenn said. “Although people may feel as if they can combat sleep deprivation with caffeine, their performance on higher-level tasks will likely still be impaired.”

The research was led by Philipp Thölke, a research trainee at UdeM's Cognitive and Computational Neuroscience Laboratory (CoCo Lab), and co-led by the lab's director Karim Jerbi, a psychology professor and researcher at Mila - Quebec AI Institute. ... They showed for the first first time that caffeine increases the complexity of brain signals and enhances brain "criticality" during sleep.

While caffeine can enhance alertness and improve performance on some simple cognitive tasks during sleep deprivation, it does not fully replicate the restorative benefits of actual sleep and its effectiveness can vary for complex cognitive functions. It primarily masks the effects of fatigue rather than reversing the underlying physiological impacts of sleep loss.