A code for spatial alternation during fixation in rat hippocampal CA1 neurons
A code for spatial alternation during fixation in rat hippocampal CA1 neurons
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大鼠海马 CA1 神经元固定过程中空间交替的代码
DOI：
10.1152/jn.91159.2008
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发表时间：
2009
影响因子：
2.5
通讯作者：
M.
中科院分区：
文献类型：
--
作者：
Takahashi;M.;Lauwereyns;J.;Sakurai;Y. and Tsukada;M.
海马CA1区“位置细胞”的经典概念，其活动跟踪物理位置，近年来经历了实质性的修订。在这里，我们提供了海马CA1区的抽象空间代码的进一步证据，它依赖于记忆，并增加了基本的“位置细胞”的复杂性。使用鼻子戳范式与四只雄性Wistar大鼠，我们专门集中在固定过程中的活动，当大鼠不动，等待下一个任务事件在记忆引导的空间交替任务。老鼠不得不在没有任何感官提示的情况下，依靠对一系列试验的内部表征，在一次又一次的试验中交替选择左右两个洞。在每只大鼠的右侧CA1中长期植入12个四极用于单单位记录。我们专注于76个单一的神经元，在固定期间与试验之间的基线活动相比，表现出显着的激活。在这76个固定神经元中，我们观察到38个神经元，系统地改变了他们的固定活动作为交替序列的函数。也就是说，即使这些大鼠在固定期间是不动的，神经元在应该留下下一个空间选择的试验中也会不同地放电（即，右向左试验）与下一个空间选择应该是正确的试验（即，左至右试验），反之亦然。我们的研究结果表明，这些神经元保持交替任务期间所需的空间响应的顺序代码，从而提供抽象的信息，来自内存，可用于有效的导航。
The classical notion of hippocampal CA1 “place cells,” whose activity tracks physical locations, has undergone substantial revision in recent years. Here, we provide further evidence of an abstract spatial code in hippocampal CA1, which relies on memory and adds complexity to the basic “place cell.” Using a nose-poking paradigm with four male Wistar rats, we specifically concentrated on activity during fixation, when the rat was immobile and waiting for the next task event in a memory-guided spatial alternation task. The rat had to alternate between choosing the right and left holes on a trial-by-trial basis, without any sensory cue, and relying on an internal representation of the sequence of trials. Twelve tetrodes were chronically implanted for single-unit recording in the right CA1 of each rat. We focus on 76 single neurons that showed significant activation during the fixation period compared with baseline activity between trials. Among these 76 fixation neurons, we observed 38 neurons that systematically changed their fixation activity as a function of the alternation sequence. That is, even though these rats were immobile during the fixation period, the neurons fired differently for trials in which the next spatial choice should be left (i.e., RIGHT-TO-LEFT trials) compared with trials in which the next spatial choice should be right (i.e., LEFT-TO-RIGHT trials), or vice versa. Our results imply that these neurons maintain a sequential code of the required spatial response during the alternation task and thus provide abstract information, derived from memory, that can be used for efficient navigation.