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Bidirectional control of CNS capillary diameter by pericytes
Claire M Peppiatt1, Clare Howarth, Peter Mobbs
1Department of Physiology, University College London, Gower Street, London WC1E 6BT, UK.
Nature
|October 13, 2006
Summary
Pericytes, cells lining brain capillaries, can control blood flow. This discovery challenges traditional views and may explain functional imaging signals and CNS vascular diseases.
Area of Science:
- Neuroscience
- Vascular Biology
- Cell Biology
Background:
- Neural activity drives local blood flow in the central nervous system (CNS), underpinning functional imaging like BOLD and PET.
- Traditionally, arterioles were thought to regulate CNS blood flow, but most noradrenergic innervation targets capillaries.
Purpose of the Study:
- To investigate the role of pericytes in regulating CNS capillary diameter and blood flow.
- To determine if pericytes initiate blood flow control signals.
Main Methods:
- Studied pericyte function in whole retina and cerebellar slices.
- Utilized electrical stimulation, superfusion of ATP, noradrenaline, and glutamate.
- Examined responses to GABA receptor blockers and simulated ischemia.
Main Results:
- Electrical stimulation of retinal pericytes caused localized capillary constriction that propagated to other pericytes.
- ATP and noradrenaline induced pericyte-mediated capillary constriction; glutamate reversed noradrenaline effects.
- Pericyte constriction was also triggered by GABA receptor blockers and occurred during simulated ischemia.
Conclusions:
- Pericytes actively control capillary diameter, challenging the traditional view of arteriolar regulation.
- Pericytes likely modulate CNS blood flow in response to neural activity, potentially contributing to functional imaging signals and CNS vascular diseases.
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