Relevance of synaptic tagging and capture to the persistence of long-term potentiation and everyday spatial memory
Relevance of synaptic tagging and capture to the persistence of long-term potentiation and everyday spatial memory
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DOI：
10.1073/pnas.1008638107
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发表时间：
2010-11-09
影响因子：
11.1
通讯作者：
Morris, Richard G. M.
中科院分区：
文献类型：
--
作者：
Wang, Szu-Han;Redondo, Roger L.;Morris, Richard G. M.
对无关紧要的事件的记忆会逐渐消失，除非这些事件发生在其他新奇或令人惊讶的事件之前或之后。然而，我们对新奇增强记忆持久性的神经生物学机制的理解主要限于厌恶或恐惧相关的记忆。现在，我们概述了一个“日常食欲”的行为模型，以检查是否以及如何无关的新奇促进持久性的spatialmemory耦合到并行电生理研究的持久性的长时程增强（LTP）。在连续的几天里，老鼠每天被要求在不同的地方寻找食物，然后回忆当天的位置。这个任务是海马和NMDA受体依赖性的。首先，编码低奖励诱导的地方记忆衰减超过24小时，在平行，弱强直的CA 1突触在脑切片诱导早期LTP褪色到基线。第二，新奇的探索计划30分钟后，这种弱编码导致持久的地方记忆;同样，强强直-类似于新奇-都诱导晚LTP和拯救早到晚LTP的独立，但收敛的途径。第三，海马多巴胺D1/D5受体阻断或蛋白质合成抑制15分钟内的探索防止持久的位置记忆和阻断LTP。第四，对称地，当空间记忆使用强奖励编码时，这种记忆持续24小时，除非编码发生在海马D1/D5受体阻断下。在此编码之前的新奇探索挽救了药物诱导的记忆障碍。在LTP中观察到平行效应。这些发现可以用突触标记和捕获假说来解释。
Memory for inconsequential events fades, unless these happen before or after other novel or surprising events. However, our understanding of the neurobiological mechanisms of novelty-enhanced memory persistence is mainly restricted to aversive or fear-associated memories. We now outline an "everyday appetitive" behavioral model to examine whether and how unrelated novelty facilitates the persistence of spatialmemory coupled to parallel electrophysiological studies of the persistence of long-term potentiation (LTP). Across successive days, rats were given one trial per day to find food in different places and later had to recall that day's location. This task is both hippocampus and NMDA receptor dependent. First, encoding with low reward induced place memory that decayed over 24 h; in parallel, weak tetanization of CA1 synapses in brain slices induced early-LTP fading to baseline. Second, novelty exploration scheduled 30 min after this weak encoding resulted in persistent place memory; similarly, strong tetanization-analogous to novelty-both induced late-LTP and rescued early-into late-LTP on an independent but convergent pathway. Third, hippocampal dopamine D1/D5 receptor blockade or protein synthesis inhibition within 15 min of exploration prevented persistent place memory and blocked late-LTP. Fourth, symmetrically, when spatial memory was encoded using strong reward, this memory persisted for 24 h unless encoding occurred under hippocampal D1/D5 receptor blockade. Novelty exploration before this encoding rescued the drug-induced memory impairment. Parallel effects were observed in LTP. These findings can be explained by the synaptic tagging and capture hypothesis.