Migues Paola Virginia, Hardt Oliver, Finnie Peter, Wang Yu Wang, Nader Karim
Psychology Department, McGill University, Montreal, Quebec, Canada.
Hippocampus. 2014 Sep;24(9):1112-9. doi: 10.1002/hipo.22295. Epub 2014 May 2.
The maintenance of established memories has recently been shown to involve the stabilization of GluA2-containing AMPA receptors (GluA2/AMPARs) at postsynaptic membranes. Previous studies have suggested that N-ethylmaleimide-sensitive factor (NSF) regulates the stabilization of AMPARs at the synaptic membrane. We therefore disrupted the interaction between GluA2 and NSF in the dorsal hippocampus and examined its effect on the maintenance of object location and contextual fear memory. We used two interference peptides, pep2m and pepR845A, that have been shown to block the binding of NSF to GluA2 and reduce GluA2 synaptic content. Either peptide disrupted consolidated memory, and these effects persisted for at least 5 or 28 days after peptide administration. Following peptide administration and long-term memory disruption, rats were able to acquire new memories. Memory acquisition or consolidation was not impaired when pepR845A was given immediately before the training sessions. Blocking GluA2 endocytosis with the peptide GluA23Y prevented the memory impairment effect of pepR845A. Taken together, our results indicate that the persistence of long-term memory depends on the maintenance of a steady-state level of synaptic GluA2/AMPARs, which requires the interaction of NSF with GluA2.
近期研究表明,已建立记忆的维持涉及含GluA2的α-氨基-3-羟基-5-甲基-4-异恶唑丙酸受体(GluA2/AMPARs)在突触后膜的稳定。先前的研究提示,N-乙基马来酰亚胺敏感因子(NSF)调节AMPARs在突触膜的稳定。因此,我们破坏了背侧海马中GluA2与NSF之间的相互作用,并检测其对物体位置记忆和情境恐惧记忆维持的影响。我们使用了两种干扰肽pep2m和pepR845A,它们已被证明可阻断NSF与GluA2的结合并降低GluA2的突触含量。两种肽均可破坏巩固的记忆,且这些作用在肽给药后至少持续5天或28天。在肽给药及长期记忆破坏后,大鼠能够获得新的记忆。在训练前即刻给予pepR845A时,记忆获得或巩固未受损害。用肽GluA23Y阻断GluA2内吞作用可防止pepR845A的记忆损害效应。综上所述,我们的结果表明,长期记忆的持续取决于突触GluA2/AMPARs稳态水平的维持,而这需要NSF与GluA2的相互作用。