How does hunger influence sense of smell? Implications for food reward.

Hunger can tune our sense of smell to help find food, identify foods high in calories and affect memories associated with food. Currently, we do not understand how the parts of the brain influencing smell are connected to, and influence, parts of the brain controlling food intake and food reward and food memory Ghrelin is a hormone released from the stomach during times of hunger (fasting, calorie restriction etc) that informs the brain of low energy availability. Intriguingly ghrelin targets the region of the brain response for olfaction (smell) and there is a high density of ghrelin receptors in this region. Ghrelin increases food intake, food reward and food memory although these studies ascribe the results to changes in hypothalamic and hippocampal function. As yet, there is very little information regarding the role of ghrelin receptor neurons in the olfactory bulb (region controlling smell). This project aims to understand the role of ghrelin receptors in the olfactory bulb on food intake, food reward and food memory Project Aims: • Characterise the anatomical projection targets of Ghrelin receptor neurons in the olfactory bulb.. • Record ghrelin receptor neurons in the olfactory bulb during behavioural tasks relevant to food intake and seeking. • Determine the role of ghrelin receptors in the olfactory bulb on food intake, food reward and food memory..