title: Tetrahydropalmatine protects against methamphetamine-induced spatial learning and memory impairment in mice.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of methamphetamine (MA) on spatial learning and memory and the role of tetrahydropalmatine (THP) in MA-induced changes in these phenomena in mice.
  
  
  METHODS
  Male C57BL/6 mice were randomly divided into eight groups, according to different doses of MA, different doses of THP, treatment with both MA and THP, and saline controls. Spatial learning and memory were assessed using the Morris water maze. Western blot was used to detect the expression of extracellular signal-regulated protein kinase (ERK) in the mouse prefrontal cortex (PFC) and hippocampus.
  
  
  RESULTS
  Repeated MA treatment significantly increased the escape latency in the learning phase and decreased the number of platform site crossings in the memory-test phase. ERK1/2 expression was decreased in the PFC but not in the hippocampus of the MA-treated mice. Repeated THP treatment alone did not affect the escape latency, the number of platform site crossings or the total ERK1/2 expression in the brain. Statistically significantly shorter escape latencies and more platform site crossings occurred in MA+THP-treated mice than in MA-treated mice.
  
  
  CONCLUSIONS
  Repeated MA administration impairs spatial learning and memory in mice, and its co-administration with THP prevents this impairment, which is probably attributable to changed ERK1/2 expression in the PFC. This study contributes to uncovering the mechanism underlying MA abuse, and to exploring potential therapies.
authors.affiliation: Department of Immunology and Pathogenic Biology, Xi'an Jiaotong University School of Medicine, Xi'an 710061, China.
authors.forename: Yan-Jiong
authors.initials: YJ
authors.lastname: Chen
authors.forename: Yan-Ling
authors.initials: YL
authors.lastname: Liu
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhong
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Yu
authors.forename: Hong-Liang
authors.initials: HL
authors.lastname: Su
authors.forename: Haroldo A
authors.initials: HA
authors.lastname: Toque
authors.forename: Yong-Hui
authors.initials: YH
authors.lastname: Dang
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.forename: Ming
authors.initials: M
authors.lastname: Xu
authors.forename: Teng
authors.initials: T
authors.lastname: Chen
mesh_terms: D000818:Animals; D001600:Berberine Alkaloids / Q000494:pharmacology*; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007858:Learning / Q000187:drug effects* / Q000502:physiology; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D008568:Memory / Q000187:drug effects* / Q000502:physiology; D008694:Methamphetamine / Q000633:toxicity*; D051379:Mice; D008810:Mice, Inbred C57BL; D017397:Prefrontal Cortex / Q000187:drug effects / Q000378:metabolism; D020011:Protective Agents / Q000494:pharmacology
chemical_list: D001600:Berberine Alkaloids; D020011:Protective Agents; C014215:tetrahydropalmatine; D008694:Methamphetamine; D048049:Extracellular Signal-Regulated MAP Kinases