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.
J Neurosci. 2001 Mar 1;21(5):1635-44. doi: 10.1523/JNEUROSCI.21-05-01635.2001.
To explore the plastic representation of information in spatially selective hippocampal pyramidal neurons, we made multiple single-unit recordings in rats trained to find a hidden platform at a constant location in a hippocampal-dependent annular watermaze task. Hippocampal pyramidal cells exhibited place-related firing in the watermaze. Place fields tended to accumulate near the platform, even in probe trials without immediate escape. The percentage of cells with peak activity around the hidden platform was more than twice the percentage firing in equally large areas elsewhere in the arena. The effect was independent of the actual position of the platform in the room frame. It was dissociable from ongoing motor behavior and was not related to linear or angular speed, swim direction, or variation in hippocampal theta activity. There was no accumulation of firing in any particular region in rats that were trained with a variable platform location. These training-dependent effects suggest that regions of particular behavioral significance may be over-represented in the hippocampal spatial map, even when these regions are completely unmarked.
为了探究空间选择性海马锥体细胞中信息的可塑性表征，我们在经过训练以在海马依赖性环形水迷宫任务中于固定位置找到隐藏平台的大鼠身上进行了多次单单元记录。海马锥体细胞在水迷宫中表现出与位置相关的放电活动。位置野倾向于在平台附近聚集，即使在没有立即逃脱的探索试验中也是如此。在隐藏平台周围具有峰值活动的细胞百分比是在竞技场其他同样大小区域放电细胞百分比的两倍多。这种效应与平台在房间坐标系中的实际位置无关。它与正在进行的运动行为可分离，并且与线速度或角速度、游泳方向或海马θ活动的变化无关。在用可变平台位置进行训练的大鼠中，任何特定区域都没有放电聚集。这些依赖于训练的效应表明，即使这些区域完全没有标记，具有特定行为意义的区域在海马空间图谱中可能会被过度表征。
