Penner Marsha R, Mizumori Sheri J Y
Laboratory of Neural Systems, Decision Science, Learning and Memory, Department of Psychology, University of Washington Seattle, WA, USA.
Front Aging Neurosci. 2012 Aug 8;4:22. doi: 10.3389/fnagi.2012.00022. eCollection 2012.
Studies of the neural mechanisms of navigation and context discrimination have generated a powerful heuristic for understanding how neural codes, circuits, and computations contribute to accurate behavior as animals traverse and learn about spatially extended environments. It is assumed that memories are updated as a result of spatial experience. The mechanism, however, for such a process is not clear. Here we suggest that one revealing approach to study this issue is to integrate our knowledge about limbic system mediated navigation and context discrimination with knowledge about how midbrain neural circuitry mediates decision-making. This perspective should lead to new and specific neural theories about how choices that we make during navigation determine what information is ultimately learned and remembered. This same circuitry may be involved when past experiences come to bias future spatial perceptions and response selection. With old age come not only important changes in limbic system operations, but also significant decline in the function of midbrain regions that underlie accurate and efficient decisions. Thus, suboptimal accuracy of spatial context-based decision-making may be, at least in part, responsible for the common observation of spatial memory decline in old age.
对导航和情境辨别神经机制的研究，为理解神经编码、神经回路及神经计算如何在动物穿越并了解空间扩展环境时促成准确行为，提供了一个有力的启发式方法。人们认为记忆会因空间体验而更新。然而，这一过程的机制尚不清楚。在此，我们提出一种揭示该问题的研究方法，即将我们关于边缘系统介导的导航和情境辨别的知识，与中脑神经回路如何介导决策的知识相结合。这种观点应能引出关于我们在导航过程中所做选择如何决定最终学到和记住的信息的全新且具体的神经理论。当过去的经历影响未来的空间感知和反应选择时，可能涉及相同的神经回路。随着年龄增长，不仅边缘系统的运作会发生重要变化，而且构成准确高效决策基础的中脑区域功能也会显著衰退。因此，基于空间情境的决策准确性欠佳，可能至少部分地导致了老年时常见的空间记忆衰退现象。
