Hollup S A, Molden S, Donnett J G, Moser M B, Moser E I
Department of Psychology, Norwegian University of Science and Technology, 7491 Trondheim, Norway.
Eur J Neurosci. 2001 Mar;13(6):1197-208. doi: 10.1046/j.0953-816x.2001.01487.x.
To provide a background for studying place-related activity in hippocampal neurons during spatial learning, we compared the activity of hippocampal place cells in an annular watermaze and an analogous land-based task. Complex-spike cells had robust place correlates in both conditions, and a significant proportion of the cells had place fields at the same locations. However, the in-field firing rates were slightly higher in the wet condition. Elevated firing was observed also in an open water task. There was no enhancement when the platform location was varied randomly or when there was no platform at all. Second, the place fields were under stronger directional modulation during swimming. In the annular task, directional sensitivity appeared regardless of whether the animals were trained to find a platform or not. There were directionally modulated units also in the open watermaze, but the number was smaller than in the corridor. Altogether, these observations suggest that place fields in the watermaze are largely controlled by the same factors as on dry land, in spite of the differences in kinaesthetic and vestibular input. Differences in firing rate and directional control may depend on the geometric and cognitive structure of the task rather than the medium on which the rats are moving.
为了给研究空间学习过程中海马神经元与位置相关的活动提供背景，我们比较了海马位置细胞在环形水迷宫和类似陆地任务中的活动。在两种条件下，复杂棘波细胞都有很强的位置相关性，并且相当一部分细胞在相同位置有位置野。然而，在湿环境条件下，场内放电率略高。在开放水域任务中也观察到放电增加。当平台位置随机变化或根本没有平台时，没有增强现象。其次，在游泳过程中位置野受到更强的方向调制。在环形任务中，无论动物是否经过寻找平台的训练，都出现了方向敏感性。在开放水迷宫中也有方向调制单元，但数量比在走廊中少。总之，这些观察结果表明，尽管动觉和前庭输入存在差异，但水迷宫中的位置野在很大程度上受与旱地相同的因素控制。放电率和方向控制的差异可能取决于任务的几何和认知结构，而不是大鼠移动的介质。
