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.

自发的缓慢振荡相关的慢波活动代表了一种内部产生的状态，其特征是网络静止和神经元活动的定型发作（慢波事件）交替出现。但是，尚不清楚哪个宏观信号与慢波节奏的这些有效周期有关。我们使用皮质和丘脑中局部神经群体的基于光纤的钙记录来检测异氟烷麻醉大鼠的神经生理学定义的慢钙波。各个慢波事件用于同时采集的全脑BOLD fMRI的事件相关分析。我们确定了与慢速钙波发作直接相关的BOLD反应，揭示了整个皮层范围内的BOLD相关性：整个皮层都参与了这种特定类型的慢波活动。