Wilson Jonathan J, Harding Elizabeth, Fortier Mathilde, James Benjamin, Donnett Megan, Kerslake Alasdair, O'Leary Alice, Zhang Ningyu, Jeffery Kate
Institute of Behavioural Neuroscience, Research Department of Experimental Psychology, Division of Psychology and Language Sciences, University College London, United Kingdom.
Institute of Behavioural Neuroscience, Research Department of Experimental Psychology, Division of Psychology and Language Sciences, University College London, United Kingdom.
Behav Brain Res. 2015 Aug 1;289:125-32. doi: 10.1016/j.bbr.2015.04.035. Epub 2015 Apr 27.
We tested whether mice can represent locations distributed throughout three-dimensional space, by developing a novel three-dimensional radial arm maze. The three-dimensional radial maze, or "radiolarian" maze, consists of a central spherical core from which arms project in all directions. Mice learn to retrieve food from the ends of the arms without omitting any arms or re-visiting depleted ones. We show here that mice can learn both a standard working memory task, in which all arms are initially baited, and also a reference memory version in which only a subset are ever baited. Comparison with a two-dimensional analogue of the radiolarian maze, the hexagon maze, revealed equally good working-memory performance in both mazes if all the arms were initially baited, but reduced working and reference memory in the partially baited radiolarian maze. This suggests intact three-dimensional spatial representation in mice over short timescales but impairment of the formation and/or use of long-term spatial memory of the maze. We discuss potential mechanisms for how mice solve the three-dimensional task, and reasons for the impairment relative to its two-dimensional counterpart, concluding with some speculations about how mammals may represent three-dimensional space.
我们通过开发一种新型的三维放射状臂迷宫，测试小鼠是否能够表征分布在三维空间中的位置。三维放射状迷宫，即“放射虫”迷宫，由一个中央球形核心组成，臂从该核心向各个方向伸出。小鼠学会从臂的末端获取食物，不会遗漏任何臂或再次访问已空的臂。我们在此表明，小鼠既能学会标准的工作记忆任务（其中所有臂最初都放置了诱饵），也能学会参考记忆版本（其中只有一部分臂放置了诱饵）。与放射虫迷宫的二维类似物六边形迷宫进行比较发现，如果所有臂最初都放置了诱饵，两种迷宫中的工作记忆表现同样良好，但在部分放置诱饵的放射虫迷宫中，工作记忆和参考记忆会降低。这表明小鼠在短时间尺度上具有完整的三维空间表征，但迷宫的长期空间记忆的形成和/或使用受到损害。我们讨论了小鼠解决三维任务的潜在机制，以及相对于其二维对应物受损的原因，最后对哺乳动物如何表征三维空间进行了一些推测。
