The receptive field of a neuron describes the regions of a stimulus space where the neuron is consistently active. Sparse spiking outside of the receptive field is often considered to be noise, rather than a reflection of information processing. Whether this characterization is accurate remains unclear. We therefore contrasted the sparse, temporally isolated spiking of hippocampal CA1 place cells to the consistent, temporally adjacent spiking seen within their spatial receptive fields ("place fields"). We found that isolated spikes, which occur during locomotion, are strongly phase coupled to hippocampal theta oscillations and transiently express coherent nonlocal spatial representations. Further, prefrontal cortical activity is coordinated with and can predict the occurrence of future isolated spiking events. Rather than local noise within the hippocampus, sparse, isolated place cell spiking reflects a coordinated cortical-hippocampal process consistent with the generation of nonlocal scenario representations during active navigation.

中文翻译：

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前额皮质活动预测空间导航过程中非局部海马表征的发生。


神经元的感受野描述了神经元持续活跃的刺激空间区域。感受野之外的稀疏尖峰通常被认为是噪声，而不是信息处理的反映。这种描述是否准确仍不清楚。因此，我们将海马 CA1 位置细胞稀疏的、时间上孤立的尖峰与在其空间感受野（“位置场”）内看到的一致的、时间上相邻的尖峰进行了对比。我们发现运动过程中发生的孤立尖峰与海马θ振荡强烈相位耦合，并瞬时表达相干的非局部空间表征。此外，前额皮质活动与未来孤立的尖峰事件相协调并可以预测其发生。稀疏、孤立的位置细胞尖峰不是海马体内的局部噪声，而是反映了协调的皮质-海马过程，与主动导航期间非局部场景表征的生成一致。