RT Journal Article SR Electronic T1 Glial Cells Dilate and Constrict Blood Vessels: A Mechanism of Neurovascular Coupling JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 2862 OP 2870 DO 10.1523/JNEUROSCI.4048-05.2006 VO 26 IS 11 A1 Monica R. Metea A1 Eric A. Newman YR 2006 UL http://www.jneurosci.org/content/26/11/2862.abstract AB Neuronal activity evokes localized changes in blood flow. Although this response, termed neurovascular coupling, is widely used to monitor human brain function and diagnose pathology, the cellular mechanisms that mediate the response remain unclear. We investigated the contribution of glial cells to neurovascular coupling in the acutely isolated mammalian retina. We found that light stimulation and glial cell stimulation can both evoke dilation or constriction of arterioles. Light-evoked and glial-evoked vasodilations were blocked by inhibitors of cytochrome P450 epoxygenase, the synthetic enzyme for epoxyeicosatrienoic acids. Vasoconstrictions, in contrast, were blocked by an inhibitor of ω-hydroxylase, which synthesizes 20-hydroxyeicosatetraenoic acid. Nitric oxide influenced whether vasodilations or vasoconstrictions were produced in response to light and glial stimulation. Light-evoked vasoactivity was blocked when neuron-to-glia signaling was interrupted by a purinergic antagonist. These results indicate that glial cells contribute to neurovascular coupling and suggest that regulation of blood flow may involve both vasodilating and vasoconstricting components.