in vivo 3D Morphology of Astrocyte—Vasculature Interactions in the Somatosensory Cortex: Implications for Neurovascular Coupling
Open Access
- 8 December 2010
- journal article
- Published by SAGE Publications in Journal of Cerebral Blood Flow & Metabolism
- Vol. 31 (3), 795-806
- https://doi.org/10.1038/jcbfm.2010.204
Abstract
Astrocytes are increasingly believed to play an important role in neurovascular coupling. Recent in vivo studies have shown that intracellular calcium levels in astrocytes correlate with reactivity in adjacent diving arterioles. However, the hemodynamic response to stimulation involves a complex orchestration of vessel dilations and constrictions that spread rapidly over wide distances. In this work, we study the three-dimensional cytoarchitecture of astrocytes and their interrelations with blood vessels down through layer IV of the mouse somatosensory cortex using in vivo two-photon microscopy. Vessels and astrocytes were visualized through intravenous dextran-conjugated fluorescein and cortically applied sulforhodamine 101 (SR101), respectively. In addition to exploring astrocyte density, vascular proximity, and microvascular density, we found that sheathing of subpial vessels by astrocyte processes was continuous along all capillaries, arterioles, and veins, comprising a highly interconnected pathway through which signals could feasibly be relayed over long distances via gap junctions. An inner SR101-positive sheath noted along pial and diving arterioles was determined to be nonastrocytic, and appears to represent selective SR101 staining of arterial endothelial cells. Our findings underscore the intimate relationship between astrocytes and all cortical blood vessels, and suggest that astrocytes could influence neurovascular regulation at a range of sites, including the capillary bed and pial arterioles.Keywords
This publication has 40 references indexed in Scilit:
- High-speed vascular dynamics of the hemodynamic responseNeuroImage, 2011
- Astrocytic endfoot Ca 2+ and BK channels determine both arteriolar dilation and constrictionProceedings of the National Academy of Sciences of the United States of America, 2010
- Spatiotemporal precision and hemodynamic mechanism of optical point spreads in alert primatesProceedings of the National Academy of Sciences of the United States of America, 2009
- Astrocytes are a key conduit for upstream signaling of vasodilation during cerebral cortical neuronal activation in vivoAmerican Journal of Physiology-Heart and Circulatory Physiology, 2008
- Depth-resolved optical imaging and microscopy of vascular compartment dynamics during somatosensory stimulationNeuroImage, 2007
- Penetrating arterioles are a bottleneck in the perfusion of neocortexProceedings of the National Academy of Sciences of the United States of America, 2007
- Redefining the concept of reactive astrocytes as cells that remain within their unique domains upon reaction to injuryProceedings of the National Academy of Sciences of the United States of America, 2006
- Bidirectional control of CNS capillary diameter by pericytesNature, 2006
- Sulforhodamine 101 as a specific marker of astroglia in the neocortex in vivoNature Methods, 2004
- Neuron-to-astrocyte signaling is central to the dynamic control of brain microcirculationNature Neuroscience, 2002