Astrocyte Regulation of Blood Flow in the Brain

I'm sure we need better blood flow in our brains. What is your doctor doing with this knowledge to help your brain get better blood flow? A stroke protocol perhaps?
http://cshperspectives.cshlp.org/content/early/2015/03/27/cshperspect.a020388.abstract

1. Brian A. MacVicar1 and
2. Eric A. Newman2

+ Author Affiliations

1. ¹Djavad Mowafaghian Centre for Brain Health, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia V6T 2B5, Canada
2. ²Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota 55455

1. Correspondence: ean@umn.edu

Abstract

Neuronal activity results in increased blood flow in the brain, a response named functional hyperemia. Astrocytes play an important role in mediating this response. Neurotransmitters released from active neurons evoke Ca²⁺ increases in astrocytes, leading to the release of vasoactive metabolites of arachidonic acid from astrocyte endfeet onto blood vessels. Synthesis of prostaglandin E2 (PGE2) and epoxyeicosatrienoic acids (EETs) dilate blood vessels, whereas 20-hydroxyeicosatetraenoic acid (20-HETE) constricts vessels. The release of K⁺ from astrocyte endfeet may also contribute to vasodilation. Oxygen modulates astrocyte regulation of blood flow. Under normoxic conditions, astrocytic Ca²⁺ signaling results in vasodilation, whereas under hyperoxic conditions, vasoconstriction is favored. Astrocytes also contribute to the generation of vascular tone. Tonic release of both 20-HETE and ATP from astrocytes constricts vascular smooth muscle cells, generating vessel tone. Under pathological conditions, including Alzheimer’s disease and diabetic retinopathy, disruption of normal astrocyte physiology can compromise the regulation of blood flow.