Avni Reut, Zadicario Pazit, Eilam David
Department of Zoology, Tel-Aviv University, Ramat-Aviv, Israel.
Behav Brain Res. 2006 Aug 10;171(2):313-23. doi: 10.1016/j.bbr.2006.04.006. Epub 2006 May 18.
Exploration in a dark open field undergoes three progressive changes: (i) an initial phase of spending equal amounts of time in various zones of the arena changes to staying in the corners, and ultimately spending most of the time in one corner; (ii) travel paths are first circular and scattered all over the arena, but gradually become anchored to one corner at which they start and end; (iii) traveled distance gradually decreases to that of the initial level seen in a lit open field. Altogether, rodents shift from a 'looping' exploration mechanism with feeble coupling with the environment, to 'home base' exploration which is firmly anchored to the environment. This shift also involves switching from momentary and sporadic to repeated returns to a specific, presumably familiar place, to which the animal navigates back from various other places. We suggest that this switching illustrates navigation first by directional and then by positional environmental cues, as hypothesized in the 'parallel map theory'. We also suggest that the transition from looping to home base behavior is part of a hierarchal construction of space representation via three modes of spatial information processing: (i) piloting--sequential processing, based on moving from one landmark to the next; (ii) orienting--parallel processing, based on moving from one point to the next, with the same starting and ending point; (iii) navigating--continuous processing, based on continuously updating the position in relation to several locations in the environment (map navigation).
（i）最初在场地各个区域花费相等时间的阶段，转变为待在角落，最终大部分时间都待在一个角落；（ii）行进路径最初是圆形且分散在整个场地，但逐渐固定在一个角落，从这个角落开始并结束；（iii）行进距离逐渐减少到在明亮开阔场地中最初看到的水平。总的来说，啮齿动物从与环境耦合较弱的“循环”探索机制，转变为牢固地固定在环境中的“大本营”探索机制。这种转变还涉及从短暂且零星地返回特定的、大概熟悉的地方，转变为从其他各个地方导航回到该地方的重复返回。我们认为，这种转变首先说明了通过方向环境线索然后通过位置环境线索进行导航，正如“平行地图理论”所假设的那样。我们还认为，从循环行为到“大本营”行为的转变是通过三种空间信息处理模式进行空间表征层次构建的一部分：（i）领航——顺序处理，基于从一个地标移动到下一个地标；（ii）定向——并行处理，基于从一个点移动到下一个点，起点和终点相同；（iii）导航——连续处理，基于不断更新相对于环境中几个位置的位置（地图导航）。
