Concurrent physiological multi-site calcium recordings and brain imaging: study of dynamic connectivity related to system and fluctuation states

The resting-state fMRI signal could be characterized at a single-vessel level to map vascular network connectivity in the rat brain. Translational efforts have been made to implement the single-vessel mapping scheme to investigate the vessel-specific fMRI signal fluctuation in the human brain with 3T and 9.4T MR scanners. To characterize neuro-glio-vascular dynamic changes contributing to the fMRI signal fluctuation, the fMRI signal could be simultaneously recorded with the GCaMP6-mediated neuronal and glial calcium signal in the rat cortex. The evoked and spontaneous astrocytic calcium signal represented distinct neurovascular coupling features and correlated to different states of neuronal oscillations. The spontaneous astrocytic calcium spikes may directly contribute to the slow-frequency fMRI signal fluctuation. This work is aimed to identify key coupling signals of the neuron-glial-vessel network as prognostic indicators of brain state changes in the diseased brain