Acute stress blocks the caffeine-induced enhancement of contextual memory retrieval in mice

作者：Pierard Chistophe; Ali Krazem; Henkous Nadia; Decorte Laurence; Beracochea Daniel^*

来源：European Journal of Pharmacology, 2015, 761: 70-78.

DOI：10.1016/j.ejphar.2015.011.030

• Caffeine stress
• Memory retrieval
• Anxiety
• Corticosterone
• Glucocorticoids

This study investigated in mice the dose-effect of caffeine on memory retrieval in non-stress and stress conditions. C57 BI/6 jico mice learned two consecutive discriminations (D-1 and D-2) in a four-hole board which involved either distinct contextual (CSD) or similar contextual (SSD) cues. All mice received an i.p, injection of vehicle or caffeine (8, 16 or 32 mg/kg) 30 min before the test session. Results showed that in non-stress conditions, the 16 mg/kg caffeine dose induced a significant enhancement of D-1 performance in CSD but not in SSD. Hence, we studied the effect of an acute stress (electric footshocks) administered 15 min before the test session on D-1 performance in caffeine-treated mice.
Results showed that stress significantly decreased D-1 performance in vehicle-treated controls and the memory-enhancing effect induced by the 16 mg/kg caffeine dose in non-stress condition is no longer observed. Interestingly, whereas caffeine-treated mice exhibited weaker concentrations of plasma corticosterone as compared to vehicles in non-stress condition, stress significantly increased plasma corticosterone concentrations in caffeine-treated mice which reached similar level to that of controls. Overall, the acute stress blocked both the endocrinological and memory retrieval enhancing effects of caffeine.

• 出版日期2015-8-15