School of Psychology, University of St. Andrews, St. Mary's Quad, St. Andrews, Fife Scotland, UK.
Front Neural Circuits. 2012 Mar 1;6:8. doi: 10.3389/fncir.2012.00008. eCollection 2012.
Spatial memory is a well-characterized psychological function in both humans and rodents. The combined computations of a network of systems including place cells in the hippocampus, grid cells in the medial entorhinal cortex and head direction cells found in numerous structures in the brain have been suggested to form the neural instantiation of the cognitive map as first described by Tolman in 1948. However, while our understanding of the neural mechanisms underlying spatial representations in adults is relatively sophisticated, we know substantially less about how this network develops in young animals. In this article we briefly review studies examining the developmental timescale that these systems follow. Electrophysiological recordings from very young rats show that directional information is at adult levels at the outset of navigational experience. The systems supporting allocentric memory, however, take longer to mature. This is consistent with behavioral studies of young rats which show that spatial memory based on head direction develops very early but that allocentric spatial memory takes longer to mature. We go on to report new data demonstrating that memory for associations between objects and their spatial locations is slower to develop than memory for objects alone. This is again consistent with previous reports suggesting that adult like spatial representations have a protracted development in rats and also suggests that the systems involved in processing non-spatial stimuli come online earlier.
空间记忆是人类和啮齿动物中一种特征明显的心理功能。包括海马体中的位置细胞、内嗅皮层中的网格细胞以及大脑中许多结构中的头方向细胞在内的系统网络的综合计算，被认为形成了认知地图的神经体现，这是 Tolman 于 1948 年首次描述的。然而，尽管我们对成年人中空间表示的神经机制的理解相对复杂，但我们对这个网络在年轻动物中的发展了解甚少。在本文中，我们简要回顾了研究这些系统遵循的发育时间表的研究。对非常年幼的大鼠进行的电生理记录表明，在导航经验开始时，方向信息就已经达到成年水平。然而，支持非定域记忆的系统需要更长的时间才能成熟。这与年轻大鼠的行为研究一致，这些研究表明，基于头方向的空间记忆很早就发展起来，但非定域空间记忆需要更长的时间才能成熟。我们接着报告了新的数据，证明了物体与其空间位置之间关联的记忆比单独的物体记忆发展得更慢。这再次与之前的报告一致，即表明类似成人的空间表示在大鼠中具有漫长的发展过程，也表明处理非空间刺激的系统更早地上线。
