Modeling the contribution of neuron-astrocyte cross talk to slow blood oxygenation level-dependent signal oscillations

A consistent and prominent feature of brain functional magnetic resonance imaging (fMRI) data is the presence of low-frequency (+ signaling. Specifically, neurotransmission induces pulses of Ca2 ⁺ concentration in astrocytes, resulting in increased cerebral perfusion and neuroactive transmitter release by these cells (i.e., gliotransmission), which in turn stimulates neuronal activity. Noticeably, the level of neuron-astrocyte cross talk regulates the periodic behavior of the Ca2 ⁺ wave-induced BOLD fluctuations. Our results suggest that the spontaneous ongoing activity of neuroglial networks is a potential source of the observed slow fMRI signal oscillations.