Functional Architecture of Memory unit, Mercator Research Group, Faculty of Medicine, Ruhr University Bochum, Bochum 44801, Germany(1).
Behav Brain Res. 2013 Oct 1;254:22-33. doi: 10.1016/j.bbr.2013.04.048. Epub 2013 May 3.
For the past two decades an increasing number of studies have underlined the crucial role of the immediate - early gene Arc in plasticity processes thought to sustain memory function. Because of the high spatial and temporal resolution of this technique, the detection of Arc products appears to have become a new standard for the mapping of cognitive processes. To date, most Arc studies have focused on identifying the contribution of the hippocampal subfields CA1 and CA3 to spatial processes. In contrast, few have investigated their role in non-spatial memory, or the role of other medial temporal lobe (MTL) areas in spatial and non-spatial memory. This short review describes recent studies focusing on these issues. After a brief overview of Arc's functions, we report a set of studies that put to the test some well-accepted theories in recognition memory. First, we describe data indicating that the parahippocampal areas may not be strictly segregated into spatial and non-spatial streams, as originally described. Second, we report findings revealing a functional segregation along the dorsoventral axis in CA1, but not in CA3. Finally, we bring evidence for a segregation of CA3 along the proximodistal axis and discuss the involvement of a proximal CA3-distal CA1 network during non-spatial memory. In summary, 'Arc imaging' appears to be a powerful tool to identify neural substrates of cognitive processes, not only in the hippocampus but also in the remaining of the MTL. Moreover, because of its fundamental role in synaptic processes, it offers a rare and exciting opportunity to further bridge plasticity processes and memory function.
在过去的二十年中，越来越多的研究强调了即时早期基因 Arc 在被认为维持记忆功能的可塑性过程中的关键作用。由于该技术具有高空间和时间分辨率，因此检测 Arc 产物似乎已成为映射认知过程的新标准。迄今为止，大多数 Arc 研究都集中在确定海马体 CA1 和 CA3 亚区对空间过程的贡献。相比之下，很少有研究探讨它们在非空间记忆中的作用，或其他内侧颞叶（MTL）区域在空间和非空间记忆中的作用。这篇简短的综述描述了最近关注这些问题的研究。在简要概述了 Arc 的功能之后，我们报告了一组检验识别记忆中一些公认理论的研究。首先，我们描述了一些数据，这些数据表明，正如最初描述的那样，旁海马区可能没有严格地分为空间和非空间流。其次，我们报告了发现揭示了 CA1 中沿背腹轴的功能分离，但 CA3 中没有。最后，我们提供了 CA3 沿近-远轴分离的证据，并讨论了在非空间记忆过程中近端 CA3-远端 CA1 网络的参与。总之，“Arc 成像”似乎是一种识别认知过程神经基质的有力工具，不仅在海马体中，而且在 MTL 的其余部分也是如此。此外，由于其在突触过程中的基本作用，它提供了一个难得而令人兴奋的机会，可以进一步弥合可塑性过程和记忆功能之间的差距。
