Fig. 5.

Astrocytic endfoot TRPV4 channel activation during NVC is not mediated by EETs. Brain slices were incubated with MAFP (5 μM for 20 min), an inhibitor of cytosolic and Ca²⁺-independent PLA₂, to block arachidonic acid production and the subsequent formation of cytochrome P450 (CYP) metabolites, including EETs. (A) Endfoot Ca²⁺ and parenchymal arteriole diameter responses to EFS before and after treatment with MAFP. (B, a) Incubation with MAFP dilated parenchymal arterioles before EFS (P < 0.01; n = 7 slices from four animals). In the presence of MAFP, the EFS-evoked increase in endfoot [Ca²⁺]_i did not differ from that in controls (B, b), but the evoked dilation was reduced (B, c) (P < 0.01; n = 7 slices from four animals). (Scale bar, 10 µm.) Values were compared by paired t test.