Place field repetition and spatial learning in a multicompartment environment.
Place field repetition and spatial learning in a multicompartment environment.
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DOI：
10.1002/hipo.22496
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发表时间：
2016-01
期刊：
影响因子：
3.5
通讯作者：
Dudchenko PA
中科院分区：
文献类型：
--
作者：
Grieves RM;Jenkins BW;Harland BC;Wood ER;Dudchenko PA
最近的研究表明，海马体中的位置细胞拥有在物理上相似的平行环境中重复的放电场。这些结果意味着动物在行为水平上区分平行环境应该是困难的。为了测试这一点，我们在具有四个平行隔室的环境中训练大鼠进行新的气味定位任务，这些隔室先前已被证明可以产生位置场重复。第二组动物接受了相同的任务训练，但隔间的排列方向不同，我们假设这种排列方式会产生更少的位置场重复。相对于在放射状排列的隔室中的学习，在平行隔室中的气味定位任务的学习显著受损。较少的动物获得了充分的歧视，在平行的隔间相比，在辐射状的隔间，前者也需要更多的会议，以达到标准相比，后者。为了证实隔室的排列产生了位置细胞重复的差异，在一个单独的动物组中，我们记录了两种环境中的CA1位置细胞。我们发现，CA1的位置细胞表现出重复的领域在四个平行的局部隔间，但没有这样做时，相同的隔间呈放射状排列。为了证实平行和径向隔室中位置场重复的差异取决于它们的角度排列，而不是进入迷宫外视觉标志的偶然差异，我们在没有方向标志的情况下在第二组大鼠中重复记录。我们再次发现，位置场在平行的隔间中表现出重复，而在放射状排列的隔间中则没有。因此，在这些隔室中放置场重复或缺乏重复并不依赖于迷宫外的线索。总之，这些结果意味着，地方字段重复限制空间学习。© 2015 Wiley Periodicals，Inc.
Recent studies have shown that place cells in the hippocampus possess firing fields that repeat in physically similar, parallel environments. These results imply that it should be difficult for animals to distinguish parallel environments at a behavioral level. To test this, we trained rats on a novel odor‐location task in an environment with four parallel compartments which had previously been shown to yield place field repetition. A second group of animals was trained on the same task, but with the compartments arranged in different directions, an arrangement we hypothesised would yield less place field repetition. Learning of the odor‐location task in the parallel compartments was significantly impaired relative to learning in the radially arranged compartments. Fewer animals acquired the full discrimination in the parallel compartments compared to those trained in the radial compartments, and the former also required many more sessions to reach criterion compared to the latter. To confirm that the arrangement of compartments yielded differences in place cell repetition, in a separate group of animals we recorded from CA1 place cells in both environments. We found that CA1 place cells exhibited repeated fields across four parallel local compartments, but did not do so when the same compartments were arranged radially. To confirm that the differences in place field repetition across the parallel and radial compartments depended on their angular arrangement, and not incidental differences in access to an extra‐maze visual landmark, we repeated the recordings in a second set of rats in the absence of the orientation landmark. We found, once again, that place fields showed repetition in parallel compartments, and did not do so in radially arranged compartments. Thus place field repetition, or lack thereof, in these compartments was not dependent on extra‐maze cues. Together, these results imply that place field repetition constrains spatial learning. © 2015 Wiley Periodicals, Inc.