Experimental Physiology
93.9 pp 1022-1028
DOI: 10.1113/expphysiol.2007.039461
© The Physiological Society 2008
Identification of neurocircuitry controlling cardiovascular function in humans using functional neurosurgery: implications for exercise control
Alexander L. Green1 and
David J. Paterson2
1 Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK
2 Department of Physiology, Anatomy and Genetics, University of Oxford, Sherrington Building, Parks Road, Oxford OX1 3PT, UK
The neurocircuitry underlying human cardiovascular control during exercise has yet to be fully elucidated. Functional imaging studies and animal studies have so far identified potential circuits that might be involved in the cardiovascular response to exercise, so-called central command. This brief review highlights neurocircuits that may have functional significance as judged from direct recordings of electrical activity during exercise in patients with implanted deep brain stimulating electrodes. Of particular interest is the periaqueductal grey area (PAG), where electrodes are implanted in humans to treat chronic pain. This area is known to be important in the exercise pressor reflex in animals. Our studies have shown that changes occur in this region during anticipation of exercise, indicating a possible role in the central command of cardiovascular variables before and during exercise. This leads us to suggest that the PAG may be an integrating area between the feedback signals from muscle and the feedforward signals from higher centres. The role of the PAG in cardiovascular control in humans, with reference to electrical stimulation experiments, is also described.
(Received 6 February 2008;
accepted after revision 3 June 2008; first published online 20 June 2008)
Corresponding author A. L. Green: Nuffield Department of Surgery, University of Oxford, John Radcliffe Hospital, Headley Way, Oxford OX3 9DU, UK. Email: alex.green{at}physiol.ox.ac.uk
Copyright © 2008 by the The Physiological Society.