The neurovascular unit and the role of astrocytes in the regulation of vascular tone / Jessica A. Filosa, Georgia Regents University.

Format:

Book

Author/Creator:

Filosa, Jessica A., author.

Series:

Colloquium series on neuroglia in biology and medicine ; Number 6.

Colloquium Series on Neuroglia in Biology and Medicine: From Physiology to Disease, 2375-9917 ; Number 6

Language:

English

Subjects (All):

Astrocytes.

Brain--Blood-vessels.

Brain.

Physical Description:

1 online resource (70 p.)

Place of Publication:

[San Rafael, California] : Morgan & Claypool Life Sciences, 2015.

Language Note:

English

System Details:

Mode of access: World Wide Web.

Summary:

Optimal cerebral blood flow is coordinated by functional hyperemia and cerebral autoregulation. These processes ensure that the metabolic demands of the brain are met at all times. Both in vivo and in vitro studies support a role for astrocytes in the regulation of cerebral blood flow. In this we review the cellular mechanisms contributing to astrocyte-mediated vasodilation and vasoconstriction of parenchymal arterioles. Primarily, we discuss how activity-dependent changes in astrocytic Ca2+ contribute to the release of vasoactive signals involved in neurovascular coupling. Following the rise in astrocytic Ca2+ and phospholipase A2 activation, arachidonic acid is released and metabolized into multiple vasoactive signals (e.g., prostaglandins, epoxyeicosatrienoic acids, and 20-HETE). The level of arteriole tone along with the metabolic conditions of the tissue can alter the action of these signals leading to either vasodilation or vasoconstriction. Moreover, increased Ca2+ also activates large conductance Ca2+-activated K+ channels expressed in astrocytic endfeet processes. Depending on the K+ efflux concentration released, this pathway can also elicit vasodilation or vasoconstriction of parenchymal arterioles. Finally, we conclude by discussing recent divergent in vivo findings which question a role for astrocyte in functional hyperemia.

Contents:

1. Introduction

2. Constituents of the neurovascular unit

3. Astrocyte regulation of vascular tone

3.1 Mechanisms underlying NVC-mediated vasodilation vs. vasoconstriction

3.2 Role of K+ in astrocyte-mediated vascular responses

3.3 Role of nitric oxide in astrocyte-mediated vascular responses

3.4 Influence of metabolism on NVC-mediated vascular responses

3.5 Purinergic receptor signaling and neurovascular coupling

4. Pericytes and neurovascular coupling

5. Overall considerations when studying NVC-mediated responses

Acknowledgments

References

Author biography

Titles of related interest.

Notes:

Part of: Colloquium digital library of life sciences.

Includes bibliographical references.

Description based on online resource; title from PDF title page (ebrary, viewed June 24, 2015).

Cited in:

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ISBN:

1-61504-679-8

OCLC:

911245834