Ghrelin-dependent mechanisms of food reward. Part 1. Ghrelin and dopamine

Feeding behavior includes both the satisfaction of metabolic nutrient requirements and the hedonic aspects of pleasure. The orexigenic hormone ghrelin increases motivation to food intake. In addition, by modulating the reward system, ghrelin enhances the rewarding properties of non-food stimuli. The dopaminergic mesolimbic system plays a key role in the mechanisms of reward. Ghrelin regulates the activity of this system by acting on several levels of brain organization. The hierarchy of ghrelin-sensitive neural networks, as well as afferent connections and reciprocal interactions between its components, mediating the effect of ghrelin on the process of motivation in metabolic and hedonic type of feeding are considered.