Chronic Caffeine Treatment Prevents Sleep Deprivation-Induced Impairment of Cognitive Function and Synaptic Plasticity

STUDY OBJECTIVES: This study was undertaken to provide a detailed account of the effect of chronic treatment with a small dose of caffeine on the deleterious effects of sleep loss on brain function in rats. EXPERIMENTAL DESIGN: We investigated the effects of chronic (4 weeks) caffeine treatment (0.3 g/L in drinking water) on memory impairment in acutely (24 h) sleep-deprived adult male Wistar rats. Sleep deprivation was induced using the modified multiple platform model. The effects of caffeine on sleep deprivation-induced hippocampus-dependent learning and memory deficits were studied by 3 approaches: learning and memory performance in the radial arm water maze task, electrophysiological recording of early long-term potentiation (E-LTP) in area CA1 of the hippocampus, and levels of memory- and synaptic plasticity-related signaling molecules after E-LTP induction. MEASUREMENT AND RESULTS: The results showed that chronic caffeine treatment prevented impairment of hippocampus-dependent learning, shortterm memory and E-LTP of area CA1 in the sleep-deprived rats. In correlation, chronic caffeine treatment prevented sleep deprivation-associated decrease in the levels of phosphorylated calcium/calmodulin-dependent protein kinase II (P-CaMKII) during expression of E-LTP. CONCLUSIONS: 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.