Single-trial phase precession in the hippocampus.
Single-trial phase precession in the hippocampus.
复制标题
海马体的单次试验阶段进动。
DOI：
10.1523/jneurosci.2270-09.2009
复制
发表时间：
2009-10-21
影响因子：
5.3
通讯作者：
Kempter, Richard
中科院分区：
文献类型：
--
作者：
Schmidt, Robert;Diba, Kamran;Leibold, Christian;Schmitz, Dietmar;Buzsaki, Gyoergy;Kempter, Richard
在大鼠海马锥体细胞的位置场的交叉过程中，细胞的放电相位相对于局部θ节律降低。这种相位进动通常是在许多位置场遍历汇集在一起的数据的基础上进行研究的。在这里，我们研究的性质，相位进动在单次试验。我们发现，单次试验和合并试验的相位进动是不同的相位位置相关性，相位时间相关性，和相位范围。虽然合并试验相位进动可能跨越360°，但最常见的单次试验相位范围仅为180°左右。在合并试验中，相位和位置之间的相关性（r =-0.58）强于相位和时间之间的相关性（r =-0.27），而在单一试验中，这些相关性（两者均为r =-0.61）没有显著差异。接下来，我们证明了相位进动表现出很大的试验间变异性。总的来说，只有一小部分的试验到试验的相位进动（如斜率或偏移）的措施的变化可以解释其他单一的试验属性（如运行速度或发射率），而更大的一部分的变化仍然有待解释。最后，我们发现，通过从汇总数据中随机抽取尖峰而创建的替代单一试验并不等同于实验性单一试验：因此，汇总试验改变了相位进动的基本测量。这些研究结果表明，单一的试验可能更适合编码时间结构的事件比所建议的汇总数据。
During the crossing of the place field of a pyramidal cell in the rat hippocampus, the firing phase of the cell decreases with respect to the local theta rhythm. This phase precession is usually studied on the basis of data in which many place field traversals are pooled together. Here we study properties of phase precession in single trials. We found that single-trial and pooled-trial phase precession were different with respect to phase-position correlation, phase-time correlation, and phase range. While pooled-trial phase precession may span 360°, the most frequent single-trial phase range was only around 180°. In pooled trials, the correlation between phase and position (r = −0.58) was stronger than the correlation between phase and time (r = −0.27), whereas in single trials these correlations (r = −0.61 for both) were not significantly different. Next, we demonstrated that phase precession exhibited a large trial-to-trial variability. Overall, only a small fraction of the trial-to-trial variability in measures of phase precession (e.g. slope or offset) could be explained by other single-trial properties (such as running speed or firing rate), while the larger part of the variability remains to be explained. Finally, we found that surrogate single trials, created by randomly drawing spikes from the pooled data, are not equivalent to experimental single trials: pooling over trials therefore changes basic measures of phase precession. These findings indicate that single trials may be better suited for encoding temporally structured events than is suggested by the pooled data.