The role of ghrelin in regulating synaptic function and plasticity of feeding-associated circuits
- 1University of Coimbra, Portugal
Synaptic plasticity of the neuronal circuits associated with feeding behavior is regulated by peripheral signals as a response to changes in the energy status of the body. These signals include glucose, free fatty acids, leptin and ghrelin and are released into circulation, being able to reach the brain. To date, ghrelin, a small peptide released from the stomach, is the only known orexigenic hormone produced in peripheral organs, and its action regulates food intake, body weight and glucose homeostasis. Behavioral studies show that ghrelin is implicated in the regulation of both hedonic and homeostatic feeding and of cognition. Ghrelin-induced synaptic plasticity has been described in neuronal circuits associated with these behaviors.
In this review, we discuss the neuromodulatory mechanisms induced by ghrelin in regulating synaptic plasticity in three main neuronal circuits previously associated with feeding behaviors, namely hypothalamic (homeostatic feeding), ventral tegmental (hedonic and motivational feeding) and hippocampal (cognitive) circuits. Given the central role of ghrelin in regulating feeding behaviors, and the disrupted ghrelin levels associated with metabolic disorders such as obesity and anorexia, it is of paramount relevance to understand the effects of ghrelin on synaptic plasticity of neuronal circuits associated with feeding behaviors.
Keywords: Ghrelin, synaptic plasiticty, Hypothalamus, ventral tegmental area (VTA), Hippocampus, feeding
Received: 05 Jan 2019;
Accepted: 24 Apr 2019.
Edited by:Margherita Maffei, Italian National Research Council (CNR), Italy
Reviewed by:Mario Perello, National Council for Scientific and Technical Research (CONICET), Argentina
Omar Al Massadi, Sorbonne Universités, France
Copyright: © 2019 Serrenho, Santos and Carvalho. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Ana Luisa Carvalho, University of Coimbra, Coimbra, 3000-214, Coimbra, Portugal, firstname.lastname@example.org