Spontaneous slow oscillation-associated slow wave activity represents an internally generated state which is characterized by alternations of network quiescence and stereotypical episodes of neuronal activity - slow wave events. However, it remains unclear which macroscopic signal is related to these active periods of the slow wave rhythm. We used optic fiber-based calcium recordings of local neural populations in cortex and thalamus to detect neurophysiologically defined slow calcium waves in isoflurane anesthetized rats. The individual slow wave events were used for an event-related analysis of simultaneously acquired whole-brain BOLD fMRI. We identified BOLD responses directly related to onsets of slow calcium waves, revealing a cortex-wide BOLD correlate: the entire cortex was engaged in this specific type of slow wave activity. These findings demonstrate a direct relation of defined neurophysiological events to a specific BOLD activity pattern and were confirmed for ongoing slow wave activity by independent component and seed-based analyses.

中文翻译：

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全皮质 BOLD fMRI 活动反映了局部记录的慢振荡相关钙波

自发的慢振荡相关的慢波活动代表内部生成的状态，其特征是网络静止和神经元活动的刻板发作-慢波事件的交替。然而，尚不清楚哪个宏观信号与慢波节律的这些活跃期有关。我们使用基于光纤的皮层和丘脑局部神经群体的钙记录来检测异氟醚麻醉大鼠的神经生理学定义的慢钙波。单个慢波事件用于对同时获得的全脑 BOLD fMRI 进行事件相关分析。我们确定了与慢钙波的发生直接相关的 BOLD 反应，揭示了整个皮层的 BOLD 相关性：整个皮层都参与了这种特定类型的慢波活动。