title: [NR2B-pERK1/2-pElk-1 signaling contributes to the avoidance learning and memory of rats].
abstract: OBJECTIVE
  To investigate whether NR2B-pERK1/2-pElk-1 signaling contributes to the Y-maze learning and memory of rat brain.
  
  
  METHODS
  45 adult male SD rats were divided into 4 groups: (1) Ifenprodil peritoneal injection group (Ifenprodil ip, n = 14); (2) DMSO peritoneal injection group(DMSO ip, n = 15); (3) Ifenprodil cerebral ventricle injection group (Ifenprodil ic, n = 8); (4) DMSO cerebral ventricle injection group(DMSO ic, n = 8). Y-maze training and test were used as an learning and memory enhancing stimulus. Immunohistochemical and Western blotting methods were used for detecting pERK1/2 and pElk-1 expression intensity of different brain regions.
  
  
  RESULTS
  Compared with the DMSO ip group, the ifenprodil ip group showed no change on the Y-maze learning score (P > 0.05), but its Y-maze memory score tested 24 after learning decreased (P < 0.05). Ifenprodil peritoneal injection made brain pERK1/2 and pElk-1 expression decreased generally. In hippocampus, marginal division of striatum(MrD), amygdala,these changes were more significant (P < 0.05). Compared with the DMSO ic group, the reconsolidation of Y-maze memory tested 6 hours after ifenprodil injection was impaired in ifenprodil ic group (P < 0.05). The OD value of pERK1/2 and pElk-1 positive bands in ifenprodil ic group attenuated generally. The pElk-1 positive bands of caudate putamen and MrD almost disappeared in ifenprodil ic group.
  
  
  CONCLUSIONS
  NR2B is essential for the formation of long-term memory, reconsolidation of Y-maze memory. The deactivation of NR2B by ifenprodil will impair these courses. Meanwhile, the deactivation of NR2B attenuates pERK1/2 and pElk-1 expression of learning and memory related regions after Y-maze learning and memory reconsolidation test. In MrD and caudate putamen, the pElk-1 expression are completely blocked by ifenprodil after memory reconsolidation test.
authors.affiliation: The Second Affiliated Hospital of Southern Medical University, Guangzhou 510282, China.
authors.forename: Xu-Hong
authors.initials: XH
authors.lastname: Chen
authors.forename: Si-Yun
authors.initials: SY
authors.lastname: Shu
authors.forename: Zhen-Jiang
authors.initials: ZJ
authors.lastname: Liang
authors.forename: Xin-Min
authors.initials: XM
authors.lastname: Bao
authors.forename: Li-Xue
authors.initials: LX
authors.lastname: Chen
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Wu
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008568:Memory / Q000502:physiology*; D010880:Piperidines / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism*; D050807:ets-Domain Protein Elk-1 / Q000378:metabolism*
chemical_list: C494114:Elk1 protein, rat; C121001:NR2B NMDA receptor; D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate; D050807:ets-Domain Protein Elk-1; D048049:Extracellular Signal-Regulated MAP Kinases; C010739:ifenprodil; D004121:Dimethyl Sulfoxide