Acute stress blocks the caffeine-induced enhancement of contextual memory retrieval in mice.
This study investigated in mice the dose-effect of caffeine on memory retrieval in non-stress and stress conditions. C57 Bl/6 Jico mice learned two consecutive discriminations (D1 and D2) 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 32mg/kg) 30min before the test session. Results showed that in non-stress conditions, the 16mg/kg caffeine dose induced a significant enhancement of D1 performance in CSD but not in SSD. Hence, we studied the effect of an acute stress (electric footshocks) administered 15min before the test session on D1 performance in caffeine-treated mice. Results showed that stress significantly decreased D1 performance in vehicle-treated controls and the memory-enhancing effect induced by the 16mg/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.
IRBA, Département de Toxicologie et Risques Chimiques, BP 73, 91223 Brétigny-sur-Orge Cedex, France.
Chistophe
C
Pierard
Institut de Neurosciences Cognitives et Integratives d'Aquitaine, Université de Bordeaux, UMR CNRS 5287, Avenue des Facultés, 33405 Talence Cedex, France.
Ali
A
Krazem
Institut de Neurosciences Cognitives et Integratives d'Aquitaine, Université de Bordeaux, UMR CNRS 5287, Avenue des Facultés, 33405 Talence Cedex, France.
Nadia
N
Henkous
Institut de Neurosciences Cognitives et Integratives d'Aquitaine, Université de Bordeaux, UMR CNRS 5287, Avenue des Facultés, 33405 Talence Cedex, France.
Laurence
L
Decorte
Institut de Neurosciences Cognitives et Integratives d'Aquitaine, Université de Bordeaux, UMR CNRS 5287, Avenue des Facultés, 33405 Talence Cedex, France. Electronic address: daniel.beracochea@u-bordeaux1.fr.
Daniel
D
Béracochéa
D000208:Acute Disease; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D002110:Caffeine / Q000494:pharmacology*; D003071:Cognition / Q000187:drug effects*; D003345:Corticosterone / Q000097:blood; D003463:Cues; D004192:Discrimination, Psychological / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004597:Electroshock; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008568:Memory / Q000187:drug effects*; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D013315:Stress, Psychological / Q000097:blood / Q000209:etiology / Q000523:psychology*; D013997:Time Factors
D002110:Caffeine; D003345:Corticosterone
Anxiety; Caffeine-stress; Corticosterone; Glucocorticoids; Memory retrieval