Isn't functional neuroimaging all about Ca2+ signaling in astrocytes?

Extensive research over the past decades about the multifaceted roles of brain astrocytes led to the suggestion that the signals observed with functional neuroimaging might primarily reflect astrocytic rather than neuronal activity. The basis for this paradigm-shifting concept was the evidence for an involvement of astrocytes in the control of local cerebral blood flow through intracellular Ca(2+) signaling. In this Neuro Forum, I discuss new important experimental findings obtained by Jego et al. (Jego P, Pacheco-Torres J, Araque A, Canals S. J Cereb Blood Flow Metab 34: 1599-1603, 2014) as well as other closely related studies published recently, prompting a dismissal of substantial astrocytic contribution in functional neuroimaging.