Table of Contents
International Journal of Peptides
Volume 2010, Article ID 616757, 8 pages
http://dx.doi.org/10.1155/2010/616757
Review Article

Ghrelin: Central Nervous System Sites of Action in Regulation of Energy Balance

1Department of Biological Sciences, University of Manitoba, Winnipeg, MB, Canada R3T 2N2
2Department of Physiology, Queen's University, Kingston, ON, Canada K7L 3N6

Received 31 October 2009; Accepted 8 December 2009

Academic Editor: Alessandro Laviano

Copyright © 2010 Mark Fry and Alastair V. Ferguson. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Ghrelin, a peptide hormone secreted by the stomach, has been shown to regulate energy homeostasis by modulating electrical activity of neurons in the central nervous system (CNS). Like many circulating satiety signals, ghrelin is a peptide hormone and is unable to cross the blood-brain barrier without a transport mechanism. In this review, we address the notion that the arcuate nucleus of the hypothalamus is the only site in the CNS that detects circulating ghrelin to trigger orexigenic responses. We consider the roles of a specialized group of CNS structures called the sensory circumventricular organs (CVOs), which are not protected by the blood-brain barrier. These areas include the subfornical organ and the area postrema and are already well known to be key areas for detection of other circulating hormones such as angiotensin II, cholecystokinin, and amylin. A growing body of evidence indicates a key role for the sensory CVOs in the regulation of energy homeostasis.