Role of histamine H1 receptor in caffeine induced locomotor sensitization

• Published in: Neuroscience letters 2018-03, Vol.668, p.60-66
• Main Authors: Kumar, Shalu, Verma, Lokesh, Jain, Nishant S.
• Format: Article
• Language: English
• Subjects: Caffeine; H1 receptor; Histamine; Locomotor sensitization
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2018.01.002

•Role of Histamine H1 receptor in the caffeine induced locomotor sensitization was investigated.•H1 receptor agonist enhanced while antagonist attenuated the induction of and expression to caffeine induced locomotor sensitization.•We hypothesized that H1 receptor up-regulation during caffeine administration could be responsible for these effects. The present study elucidated the role of histamine H1 receptor in the caffeine induced locomotor sensitization. Intermittent administration of caffeine (15 mg/kg, i.p.) on alternate days (induction phase) i.e. 1st, 3rd, 5th, 7th, 9th, 11th and 13th resulted in the development of locomotor sensitization. In addition, challenge with sub-stimulant dose of caffeine (10 mg/kg, i.p.) directly on 17th day to induction group animals resulted in expression to locomotor sensitization to caffeine. I.c.v. injection of histaminergic agents concomitantly with caffeine during induction phase i.e. histamine H1 receptor agonist, FMPH (6.5 μg/mouse) significantly potentiated while H1 receptor antagonist, cetirizine (0.1 μg/mouse) attenuated the locomotor sensitization induced by caffeine (15 mg/kg, i.p.). In addition, challenge with caffeine (10 mg/kg, i.p.) on the expression day (17th) to the induction group mice on FMPH + caffeine treatment showed enhanced, while those on cetirizine + caffeine treatment exhibited lesser expression to locomotor sensitization. Therefore, a possible contributory role of the central histaminergic system via H1 receptor stimulation or up-regulation in the caffeine-induced locomotor sensitizing effect is proposed.