Astrocytes and Brain Hypoxia
Astrocytes provide the structural and functional interface between the cerebral circulation and neuronal networks. They enwrap all intracerebral arterioles and capillaries, control the flux of nutrients as well as the ionic and metabolic environment of the neuropil. Astrocytes have the ability to adjust cerebral blood flow to maintain constant PO2 and PCO2 of the brain parenchyma. Release of ATP in the brainstem, presumably by local astrocytes, helps to maintain breathing and counteract hypoxia-induced depression of the respiratory network. Astrocytes also appear to be involved in mediating hypoxia-evoked changes in blood–brain barrier permeability, brain inflammation, and neuroprotection against ischaemic injury. Thus, astrocytes appear to play a fundamental role in supporting neuronal function not only in normal conditions but also in pathophysiological states when supply of oxygen to the brain is compromised.
KeywordsAdenosine Astrocytes ATP Breathing Glutamate Hypoxia Prostaglandins Vasodilation
The research in our laboratories referred to in this report was funded by The Wellcome Trust and British Heart Foundation. A.V.G. is a Wellcome Trust Senior Research Fellow (ref. 079040); G.L.A. is an Academy of Medical Sciences/Health Foundation Clinician Scientist.
- 32.Takata F, Dohgu S, Nishioku T, Takahashi H, Harada E, Makino I, Nakashima M, Yamauchi A, Kataoka Y. Adrenomedullin-induced relaxation of rat brain pericytes is related to the reduced phosphorylation of myosin light chain through the cAMP/PKA signaling pathway. Neurosci Lett. 2009;449:71–5.CrossRefPubMedGoogle Scholar