title: Modeling the contribution of neuron-astrocyte cross talk to slow blood oxygenation level-dependent signal oscillations.
abstract: A consistent and prominent feature of brain functional magnetic resonance imaging (fMRI) data is the presence of low-frequency (<0.1 Hz) fluctuations of the blood oxygenation level-dependent (BOLD) signal that are thought to reflect spontaneous neuronal activity. In this report we provide modeling evidence that cyclic physiological activation of astroglial cells produces similar BOLD oscillations through a mechanism mediated by intracellular Ca(2+) signaling. Specifically, neurotransmission induces pulses of Ca(2+) 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 Ca(2+) 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.
authors.affiliation: Dipartimento di Fisica, Sapienza Università di Roma, Rome, Italy. mauro.dinuzzo@roma1.infn.it
authors.forename: Mauro
authors.initials: M
authors.lastname: DiNuzzo
authors.forename: Tommaso
authors.initials: T
authors.lastname: Gili
authors.forename: Bruno
authors.initials: B
authors.lastname: Maraviglia
authors.forename: Federico
authors.initials: F
authors.lastname: Giove
mesh_terms: D001253:Astrocytes / Q000502:physiology*; D001683:Biological Clocks / Q000502:physiology*; D001921:Brain / Q000098:blood supply* / Q000166:cytology*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000502:physiology; D003198:Computer Simulation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008954:Models, Biological; D009474:Neurons / Q000502:physiology*; D010100:Oxygen / Q000097:blood; D012146:Rest / Q000502:physiology; D013997:Time Factors
chemical_list: D010100:Oxygen; D002118:Calcium