title: Caffeine's influence on object recognition and working-memory in prepubertal mice and its modulation by gender.
abstract: OBJECTIVE
  This study investigated the effects of intraperitoneal injection of caffeine on Y-maze working-memory and novel object recognition (NOR) in prepubertal mice.
  
  
  METHODS
  Y-maze spontaneous alternation and a novel object recognition test (consisting of acclimation, acquisition and test phases) were performed. Mice received a single dose of caffeine (10, 20, 40, 80 and 120mgkg(-1) i.p.) or vehicle, 30min before Y-maze exploration. For the NOR test, caffeine was given 30min before training and another dose 30min before test phase.
  
  
  RESULTS
  NOR time (acquisition phase) increased significantly in males at all doses of caffeine and decreased in females at 10, 20 and 40mg/kg compared to vehicle; during the test phase, novel object exploration time decreased significantly in males and increased in females at 10 and 20mg/kg only to decrease again at 120mg/kg. Recognition index decreased in males and increased in females while, males showed poor discrimination between novel and familiar objects compared to vehicle; while females showed increased discrimination between novel and familiar object at 10, 20,40 and 80mg/kg and a decrease at 120mg/kg. Y-maze spontaneous alternation improved significantly in males at 10 and 40mg/kg and decreased at 20 and 120mg/kg in females.
  
  
  CONCLUSIONS
  The findings suggest that acute caffeine injection improves non-spatial memory retention in female mice but not in males; spatial working-memory is however improved in males but not in females.
authors.affiliation: Department of Human Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomosho, Oyo State, Nigeria.
authors.forename: Adejoke Yetunde
authors.initials: AY
authors.lastname: Onaolapo
authors.affiliation: Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Osogbo, Osun State, Nigeria. Electronic address: olakunleonaolapo@yahoo.co.uk.
authors.forename: Olakunle James
authors.initials: OJ
authors.lastname: Onaolapo
keywords: Caffeine; Gender; Memory; Prepubertal; Spatial-working memory