Kovács Krisztián A
Retina Research Laboratory, Martonvásár Research Premises, Eötvös Loránd University (ELTE), Budapest, Hungary.
Front Syst Neurosci. 2020 Sep 10;14:559168. doi: 10.3389/fnsys.2020.559186. eCollection 2020.
The brain is capable of registering a constellation of events, encountered only once, as an episodic memory that can last for a lifetime. As evidenced by the clinical case of the patient HM, memories preserving their episodic nature still depend on the hippocampal formation, several years after being created, while semantic memories are thought to reside in neocortical areas. The neurobiological substrate of one-time learning and life-long storing in the brain, that must exist at the cellular and circuit level, is still undiscovered. The breakthrough is delayed by the fact that studies jointly investigating the rodent hippocampus and entorhinal cortex are mostly targeted at understanding the spatial aspect of learning. Here, we present the concept of an entorhinal cortical module, termed EPISODE module, that could explain how the representations of different elements constituting episodic memories can be linked together at the stage of encoding. The new model that we propose here reconciles the structural and functional observations made in the entorhinal cortex and explains how the downstream hippocampal processing organizes the representations into meaningful sequences.
大脑能够将仅经历过一次的一系列事件记录为一种情景记忆，这种记忆可以持续一生。正如患者HM的临床病例所证明的那样，保留其情景性质的记忆在形成数年之后仍然依赖于海马结构，而语义记忆则被认为存在于新皮质区域。大脑中一次性学习和终身存储的神经生物学基础，必然存在于细胞和神经回路层面，目前仍未被发现。由于联合研究啮齿动物海马体和内嗅皮质的研究大多旨在理解学习的空间方面，这一突破被推迟了。在此，我们提出了一个内嗅皮质模块的概念，称为情景模块（EPISODE模块），它可以解释构成情景记忆的不同元素的表征如何在编码阶段联系在一起。我们在此提出的新模型协调了在内嗅皮质中所做的结构和功能观察，并解释了下游海马体处理如何将这些表征组织成有意义的序列。
