Because regional blood flow increases in association with the increased metabolic demand generated by localized increases in neural activity, functional imaging researchers often assume that changes in blood flow are an accurate read-out of changes in underlying neural activity. An understanding of the mechanisms that link changes in neural activity to changes in blood flow is crucial for assessing the validity of this assumption, and for understanding the processes that can go wrong during disease states such as ischaemic stroke. Many studies have investigated the mechanisms of neurovascular regulation in arterioles but other evidence suggests that blood flow regulation can also occur in capillaries, because of the presence of contractile cells, pericytes, on the capillary wall. Here we review the evidence that pericytes can modulate capillary diameter in response to neuronal activity and assess the likely importance of neurovascular regulation at the capillary level for functional imaging experiments. We also discuss evidence suggesting that pericytes are particularly sensitive to damage during pathological insults such as ischaemia, Alzheimer’s disease and diabetic retinopathy, and consider the potential impact that pericyte dysfunction might have on the development of therapeutic interventions and on the interpretation of functional imaging data in these disorders.
Keywords: pericyte, capillary, neurovascular coupling, brain
Citation: Hamilton NB, Attwell D and Hall CN (2010) Pericyte-mediated regulation of capillary diameter: a component of neurovascular coupling in health and disease. Front. Neuroenerg. 2:5. doi: 10.3389/fnene.2010.00005
Received: 11 February 2010;
Paper pending published: 25 March 2010;
Accepted: 28 April 2010; Published online: 21 May 2010
Edited by:Anna Devor, University of California San Diego, USA
Reviewed by:Eric Newman, University of Minnesota, USA
Copyright: © 2010 Hamilton, Attwell and Hall. This is an open-access article subject to an exclusive license agreement between the authors and the Frontiers Research Foundation, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited.
*Correspondence: Catherine N. Hall, Department of Neuroscience, Physiology and Pharmacology, University College London, Gower St, London, WC1E 6BT, UK. e-mail: email@example.com