Figure 6. Neurovascular signalling to arterioles is mediated by NMDAR and NOS activity, and not by astrocyte Ca²⁺.

(a) Example traces and (b) mean data demonstrating that stimulation-evoked arteriole dilation is not altered when the astrocyte network is dialyzed with 30 mM BAPTA, a fast Ca²⁺-chelator, compared to a control internal solution containing 1 mM EGTA. (c-e) The P2X₁ blocker NF449 (100 nM; c), the PLA₂ inhibitor MAFP (10 μM; d) and the PLD2 blocker CAY10594 (1 μM; e) do not block stimulation-evoked arteriole dilation. (f-g) The NMDA receptor blocker D-AP5 (25 μM; f) and the NO synthase blocker L-NNA (100 μM; g) abolished the arteriole dilation. Mean data showing the effect of NF449 (h), MAFP (i), CAY10594 (i), D-AP5 (j) and L-NNA (k) on arteriole dilation. Data are shown as box and whisker plots as defined in the Statistics part of the Methods.