title: Comparison of single versus repeated methamphetamine injection induced behavioral sensitization in mice.
abstract: Repeated exposure to drugs of abuse produces a persistent behavioral sensitization to stimulants, which is often used to study drug-associated behavioral plasticity. Interestingly, even a single exposure to some drugs of abuse is sufficient to elicit long-lasting behavioral sensitization. However, few studies have directly compared the magnitude of sensitization between single versus repeated drug treatments. This study examined the magnitude and duration of single methamphetamine (METH) injection-induced behavioral sensitization and compared it to the more typical repeated drug injection-induced sensitization in mice. Different groups of mice were injected with METH (0.5, 1.0, 2.0mg/kg, i.p.) only once or daily for 7 consecutive days. A challenge dose of METH (1.0mg/kg, i.p.) was tested 7 days later. The time-course of a single METH injection-induced behavioral sensitization was assessed where METH (2.0mg/kg, i.p.) was injected and a challenge dose of METH (1.0mg/kg, i.p.) was tested after different drug-free periods. Single METH injection produced similar magnitude of behavioral sensitization as compared to repeated injection. Such a sensitized locomotor response peaked 8 days after METH injection and lasted for at least 21 days. This long lasting behavioral alteration induced by single METH injection suggests the value of future studies to explore the underlying neural mechanisms, particularly in comparison to those underlying repeated METH-induced sensitization.
authors.affiliation: Department of Physiology and Pathophysiology, Tianjin Medical University, Tianjin 300070, PR China; Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA.
authors.forename: Li
authors.initials: L
authors.lastname: Jing
authors.affiliation: School of Medicine, Tsinghua University, Beijing 100083, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, University at Buffalo, The State University of New York, Buffalo, NY 14214, USA.
authors.forename: Jun-Xu
authors.initials: JX
authors.lastname: Li
authors.affiliation: College of Chinese Materia Medica, Guangzhou University of Chinese Medicine, Guangzhou 510006, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Huang
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, PR China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Liu
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, PR China.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Li
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Liang
authors.affiliation: National Institute on Drug Dependence, Peking University, Beijing 100191, PR China. Electronic address: liangjh@bjmu.edu.cn.
authors.forename: Jian-Hui
authors.initials: JH
authors.lastname: Liang
mesh_terms: D000818:Animals; D000697:Central Nervous System Stimulants / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D008297:Male; D008694:Methamphetamine / Q000008:administration & dosage / Q000494:pharmacology*; D008810:Mice, Inbred C57BL; D009043:Motor Activity / Q000187:drug effects; D013997:Time Factors
chemical_list: D000697:Central Nervous System Stimulants; D008694:Methamphetamine
keywords: Behavioral sensitization; Methamphetamine; Repeated-dose injection; Single-dose injection