Avhandling för medicine doktorsexamen vid Sahlgrenska akademin, Institutionen för neurovetenskap och fysiologi, Sektionen för fysiologi
Addressing knowledge gaps in the brain ghrelin signalling system - its neural circuitry and role in foodlinked behaviours
Opponent: professor James Edgar McCutcheon, Institutt for psykologi), UiT Norges arktiske universitet, Tromsø, Norge
Betygsnämnd: Ville Wallenius (ordf.), Janina Seubert (KI) och Estelle Barbier (LiU)
Ordförande för disputationsakten: Anna Benrick
Why do we sometimes crave food when we’re not hungry – and lose our appetite when we really need to eat?
Our drive to seek out and consume food is essential for survival and is carefully orchestrated by the brain, which takes into account both internal signals about the energy status of the body and external ones that predict food availability, such as the sight and smell of food. But disturbances or faulty processing of this system can lead to disordered eating, whether it’s overeating, or a dangerous loss of appetite seen in conditions such as anorexia, cancer or frailty.
The work in this PhD thesis explores how the brain processes hunger and food-related behaviours, using the hormone ghrelin as a window into this system. Ghrelin is the only known circulating hormone that actively stimulates appetite, making it a powerful tool to understand how the brain regulates eating. Working with mice, this thesis focuses on how ghrelin and hunger influence specific brain areas and behaviours – not just feeding itself, but also how motivated we are to seek out food and how attentive we become to food-predicting cues from our environment.
This work identifies new brain circuits involved in hunger and food-seeking behaviour and offers new insights into how ghrelin modulates attention towards food cues. It also proposes a new, non-invasive way to activate the brain ghrelin signalling system, which holds translational value.