Conjoint control of hippocampal place cell firing by two visual stimuli. I. The effects of moving the stimuli on firing field positions.
Conjoint control of hippocampal place cell firing by two visual stimuli. I. The effects of moving the stimuli on firing field positions.
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DOI：
10.1085/jgp.116.2.191
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发表时间：
2000-08
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为了更好地了解海马位置细胞的活动是如何由感官刺激控制的，并进一步阐明位置细胞所提供的环境表征的性质，我们在标准条件下，在两种不同的视觉刺激的存在下进行了记录，并经过几次操作这些刺激。与大量早期工作一致，我们发现，当在标准条件下重复记录时，位置细胞的活动是恒定的，在标准条件下，两个刺激的中心，一张黑色卡片和一张白色卡片，在圆柱形记录室的壁上分开135°。将两个刺激旋转45°会导致位置细胞放电场的相等旋转。移除任何一张卡片并旋转另一张卡片也会导致场的旋转相等，这表明两个刺激是单独突出的。增加或减少卡分离（卡重新配置）会导致圆柱体地板的表示的拓扑失真，使得场中心相对于彼此移动。我们还发现，任何一种重新配置诱导位置细胞放电强度的位置无关的下降。我们认为，这些结果是不兼容的两个先前所述的观点的位置细胞表示，即，一个非空间的理论，其中每个位置细胞被调谐到一个任意选择的子集，可用的刺激或刚性地图理论。我们建议，我们的研究结果意味着表示是地图般的，但不是刚性的，它是能够进行拉伸，而不改变当地的安排射击场。
To better understand how hippocampal place cell activity is controlled by sensory stimuli, and to further elucidate the nature of the environmental representation provided by place cells, we have made recordings in the presence of two distinct visual stimuli under standard conditions and after several manipulations of these stimuli. In line with a great deal of earlier work, we find that place cell activity is constant when repeated recordings are made in the standard conditions in which the centers of the two stimuli, a black card and a white card, are separated by 135° on the wall of a cylindrical recording chamber. Rotating the two stimuli by 45° causes equal rotations of place cell firing fields. Removing either card and rotating the other card also causes fields to rotate equally, showing that the two stimuli are individually salient. Increasing or decreasing the card separation (card reconfiguration) causes a topological distortion of the representation of the cylinder floor such that field centers move relative to each other. We also found that either kind of reconfiguration induces a position-independent decrease in the intensity of place cell firing. We argue that these results are not compatible with either of two previously stated views of the place cell representation; namely, a nonspatial theory in which each place cell is tuned to an arbitrarily selected subset of available stimuli or a rigid map theory. We propose that our results imply that the representation is map-like but not rigid; it is capable of undergoing stretches without altering the local arrangement of firing fields.