Astrocytes mediate neurovascular signaling to capillary pericytes but not to arterioles.

ABSTRACT: Active neurons increase their energy supply by dilating nearby arterioles and capillaries. This neurovascular coupling underlies blood oxygen level-dependent functional imaging signals, but its mechanism is controversial. Canonically, neurons release glutamate to activate metabotropic glutamate receptor 5 (mGluR5) on astrocytes, evoking Ca²⁺ release from internal stores, activating phospholipase A2 and generating vasodilatory arachidonic acid derivatives. However, adult astrocytes lack mGluR5, and knockout of the inositol 1,4,5-trisphosphate receptors that release Ca²⁺ from stores does not affect neurovascular coupling. We now show that buffering astrocyte Ca²⁺ inhibits neuronally evoked capillary dilation, that astrocyte [Ca²⁺]_i is ra

SUBMITTER: Mishra A 

PROVIDER: S-EPMC5131849 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature