title: Protective effect of low dose caffeine on psychological stress and cognitive function.
abstract: Caffeine is an adrenergic antagonist that enhances neuronal activity. Psychological stress depresses cognitive function.
  
  
  
  To investigate the effects of acute and chronic low dose caffeine on anxiety-like behavior and cognitive functions of acute or chronic psychological stressed rats.
  
  
  
  Acute or chronic caffeine (3mg/kg) was administered to male Sprague Dawley rats (200-250g, n=42) before acute (cat odor) and chronic variable psychological stress (restraint overcrowding stress, elevated plus maze, cat odor, forced swimming) induction. Anxiety and cognitive functions were evaluated by hole-board and object recognition tests. The brain glutathione and malondialdehyde assays, myeloperoxidase, nitric oxide (NO), superoxide dismutase (SOD), luminol and lucigenin activity and histological examination were done. ANOVA and Student's t-test were used for statistical analysis.
  
  
  
  The depressed cognitive function with chronic stress exposure and the increased anxiety-like behavior with both stress inductions were improved via both caffeine applications (p<0.05-0.001). Both caffeine pretreatments in chronic stressed rats, and chronic caffeine in acute stressed ones reduced the elevated myeloperoxidase activities (p<0.05-0.01). The increased malondialdehyde, lucigenin and NO levels with acute stress were inhibited with chronic caffeine (p<0.05-0.01), malondialdehyde and NO levels were declined by acute caffeine (p<0.001). Acute caffeine decreased SOD activity (p<0.01) and improved glutathione (p<0.01) and luminol levels (p<0.05). The induced histological damage with both stress exposures was ameliorated with chronic caffeine.
  
  
  
  The increased anxiety-like behavior and depleted cognitive functions under stress conditions were improved with both acute and predominantly chronic caffeine pretreatments by decreasing oxidative damage parameters.
authors.affiliation: Department of Physiology, Marmara University School of Medicine, Istanbul, Turkey. Electronic address: ozgurkasimay@hotmail.com.
authors.forename: Ozgur
authors.initials: O
authors.lastname: Kasimay Cakir
authors.affiliation: Undergraduate Medical Students, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Nurfitnat
authors.initials: N
authors.lastname: Ellek
authors.affiliation: Undergraduate Medical Students, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Nabila
authors.initials: N
authors.lastname: Salehin
authors.affiliation: Undergraduate Medical Students, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Rabia
authors.initials: R
authors.lastname: Hamamcı
authors.affiliation: Undergraduate Medical Students, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Hülya
authors.initials: H
authors.lastname: Keleş
authors.affiliation: Department Histology and Embryology, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Damla Gökçeoğlu
authors.initials: DG
authors.lastname: Kayalı
authors.affiliation: Department Histology and Embryology, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Akakın
authors.affiliation: Medical Laboratory Program, Vocational School of Health Related Professions, Marmara University, Istanbul, Turkey.
authors.forename: Meral
authors.initials: M
authors.lastname: Yüksel
authors.affiliation: Department of Physiology, Marmara University School of Medicine, Istanbul, Turkey.
authors.forename: Dilek
authors.initials: D
authors.lastname: Özbeyli
mesh_terms: D000818:Animals; D002110:Caffeine / Q000627:therapeutic use*; D002415:Cats; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control*; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005106:Exploratory Behavior / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D018782:Maze Learning; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D012149:Restraint, Physical / Q000009:adverse effects; D013315:Stress, Psychological / Q000150:complications* / Q000209:etiology / Q000517:prevention & control*; D013550:Swimming / Q000523:psychology; D013997:Time Factors
chemical_list: D000697:Central Nervous System Stimulants; D017382:Reactive Oxygen Species; D009569:Nitric Oxide; D002110:Caffeine
keywords: Acute stress; Anxiety; Chronic stress; Oxidative damage; Working memory