University of Gothenburg – Sweden
Invited by Jean-Christophe Delpech (Team NutriMind – NutriNeuro)
The Aperitif: The Neurobiology of appetite and hunger
« Hunger », by definition, requires a state of energy deficit, and this powerfully drives food-seeking and food consummatory behaviours, engaging brain pathways involved in energy balance and reward. The term « appetite », however, extends to include the wish to eat something because of its desirability and palatability. It follows that eating that escapes metabolic need, that engages the reward system, is especially relevant for obesity development. In this talk we will explore the neurobiology underpinning hunger and appetite, as revealed by their engagement by ghrelin, a pro-appetite orexigenic hormone. The ghrelin receptor is distributed within the feeding networks and increased ghrelin signaling impacts on a variety of food-linked behaviors including food seeking, food anticipation, food reward, food intake and food choice. Some key issues to address are “who does what?” within these neural circuits and to what extent do these pathways respond to other orexigenic stimuli, such as from food cues. We will discuss the importance of key target populations for ghrelin, namely the agouti-related peptide neurons in the hypothalamic arcuate nucleus (that are often labelled “hunger neurons”), in the parabrachial nucleus of the brainstem (an anorexigenic center) and the ventral tegmental area dopamine reward system (for food reward and motivation).