Neural ensemble dynamics underlying a long-term associative memory.
Neural ensemble dynamics underlying a long-term associative memory.
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DOI：
10.1038/nature21682
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发表时间：
2017-03-30
期刊：
影响因子：
64.8
通讯作者：
Schnitzer MJ
中科院分区：
文献类型：
--
作者：
Grewe BF;Gründemann J;Kitch LJ;Lecoq JA;Parker JG;Marshall JD;Larkin MC;Jercog PE;Grenier F;Li JZ;Lüthi A;Schnitzer MJ
大脑关联不同刺激的能力对长期记忆至关重要，但神经集合如何编码关联记忆尚不清楚。在这里，我们研究了基底和外侧杏仁核（BLA）的细胞群如何编码条件和非条件刺激（CS，US）之间的关联。使用一个微型荧光显微镜，我们跟踪BLA合奏神经钙离子动力学在恐惧学习和灭绝行为小鼠超过六天。恐惧条件反射诱导了单个细胞CS诱发反应的上调和下调。这种双向可塑性主要发生在条件化之后，并重塑CS集成神经表征以获得与US表征的相似性。在重复CS呈现的消退训练中，CS表征变得更加独特，而不会恢复到原来的形式。在整个过程中，整体编码的CS-US关联的强度预测了每只小鼠的行为条件反射水平。这些发现支持了一个监督学习模型，在该模型中，激活的美国代表指导转换的CS代表。
The brain’s ability to associate different stimuli is vital to long-term memory, but how neural ensembles encode associative memories is unknown. Here we studied how cell ensembles in the basal and lateral amygdala (BLA) encode associations between conditioned and unconditioned stimuli (CS, US). Using a miniature fluorescence microscope, we tracked BLA ensemble neural Ca2+ dynamics during fear learning and extinction over six days in behaving mice. Fear conditioning induced both up- and down-regulation of individual cells’ CS-evoked responses. This bi-directional plasticity mainly occurred after conditioning and reshaped the CS ensemble neural representation to gain similarity to the US-representation. During extinction training with repetitive CS presentations, the CS-representation became more distinctive without reverting to its original form. Throughout, the strength of the ensemble-encoded CS-US association predicted each mouse’s level of behavioral conditioning. These findings support a supervised learning model in which activation of the US-representation guides the transformation of the CS-representation.