Hippocampal state transitions at the boundaries between trial epochs
Hippocampal state transitions at the boundaries between trial epochs
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DOI：
10.1002/hipo.23180
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发表时间：
2019-12-03
期刊：
影响因子：
3.5
通讯作者：
Smith, David M.
中科院分区：
文献类型：
--
作者：
Bulkin, David A.;Sinclair, David G.;Smith, David M.
海马体用独特的活动模式编码不同的背景。随着语境的变化，表征的变化，被称为重新映射，已经得到了广泛的研究。然而，对表示之间的转换知之甚少。在这项研究中，我们利用大鼠执行嗅觉记忆任务时所采取的神经元记录的大型数据集，该任务具有可预测的时间结构，包括试验和试验间隔（ITIs），在试验开始和试验结束时由显着的边界分开。我们发现，试验时期与稳定的海马表征相关，尽管刺激和行为的时刻到时刻的变化。代表审判和ITI时代远比空间因素将预测和两者之间的过渡是突然的。边界与多单位活性的大峰值相关，在每次试验开始或结束时，许多单个细胞特别活跃。这两个时期和边界编码的海马种群，这些代表携带的正交轴上的信息很容易识别使用主成分分析。我们认为，海马正交表示的审判和ITI时代和活动尖峰在审判边界可能有助于驱动海马活动从一个稳定状态到其他。
The hippocampus encodes distinct contexts with unique patterns of activity. Representational shifts with changes in context, referred to as remapping, have been extensively studied. However, less is known about transitions between representations. In this study, we leverage a large dataset of neuronal recordings taken while rats performed an olfactory memory task with a predictable temporal structure involving trials and intertrial intervals (ITIs), separated by salient boundaries at the trial start and trial end. We found that trial epochs were associated with stable hippocampal representations despite moment-to-moment variability in stimuli and behavior. Representations of trial and ITI epochs were far more distinct than spatial factors would predict and the transitions between the two were abrupt. The boundary was associated with a large spike in multiunit activity, with many individual cells specifically active at the start or end of each trial. Both epochs and boundaries were encoded by hippocampal populations, and these representations carried information on orthogonal axes readily identified using principal component analysis. We suggest that the hippocampus orthogonalizes representations of the trial and ITI epochs and the activity spike at trial boundaries might serve to drive hippocampal activity from one stable state to the other.