title: Caffeine and sleep-deprivation mediated changes in open-field behaviours, stress response and antioxidant status in mice.
abstract: OBJECTIVE
  Effects of daily caffeine consumption on open-field behaviours, serum corticosterone and brain antioxidant levels were investigated after six hours of total sleep-deprivation in prepubertal mice. We tested the hypothesis that daily caffeine consumption may significantly alter behaviour, stress and antioxidative response of prepubertal mice to an acute episode of total sleep-deprivation.
  
  
  METHODS
  Prepubertal Swiss mice of both sexes were assigned to two main groups of 120 each (subdivided into 6 groups of 10 each, based on sex), and administered vehicle or graded oral doses of caffeine (10, 20, 40, 80 and 120 mg/kg/day) for 14 days. On day 14, a main group was subjected to 6 h of total sleep-deprivation by 'gentle-handling'. Open-field behaviours were then assessed in both groups, after which animals were euthanized, and levels of corticosterone, superoxide dismutase and glutathione peroxidase assayed.
  
  
  RESULTS
  Horizontal locomotion, rearing and grooming increased significantly, compared to control, with sleep-deprived (SD) mice showing stronger caffeine-driven responses at higher doses; and SD female mice showing sustained response to caffeine, compared to respective males. Plasma corticosterone increased with increasing doses of caffeine in both non sleep-deprived (NSD) and SD mice; although SD mice had higher corticosterone levels. Sleep-deprivation and/or higher doses of caffeine were associated with derangements in brain antioxidant levels.
  
  
  CONCLUSIONS
  Repeated caffeine consumption and/or acute sleep-deprivation led to significant changes in pattern of open-field behaviour and stress/antioxidant response in mice. Responses seen in the study are probably due to modulatory effects of caffeine on the total body response to stressful stimuli.
authors.affiliation: Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Osogbo, Osun, Nigeria.
authors.forename: J Olakunle
authors.initials: JO
authors.lastname: Onaolapo
authors.affiliation: Department of Anatomy, Faculty of Basic Medical Sciences, College of Health Sciences, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria.
authors.forename: Y Adejoke
authors.initials: YA
authors.lastname: Onaolapo
authors.affiliation: Department of Pharmacology, Faculty of Pharmacy, Obafemi Awolowo University, Ile, Ife, Osun State, Nigeria.
authors.forename: A Moses
authors.initials: AM
authors.lastname: Akanmu
authors.affiliation: Department of Clinical Pharmacy and Pharmacy Administration, Faculty of Pharmacy, Obafemi Awolowo University, Ile, Ife, Osun State, Nigeria.
authors.forename: Gbola
authors.initials: G
authors.lastname: Olayiwola
keywords: Antioxidant; Caffeine; Open-field arena; Sex; Sleep-deprivation; Stress hormones