Guest Lecture Alexander Ross

Control of food intake - it’s all in the seasoning!

Dr. Alexander Ross, Rowett Institute of Nutrition and Health, University of Aberdeen.

The obesity epidemic points to poorly regulated food intake, leading to overconsumption in a large percentage of the human population. Strikingly however, not all humans are obese, which suggests that aberrant control of food intake lies at the heart of human obesity. Seasonal mammals are known to regulate food intake with extraordinary precision and with amplitude adjustable by daylength. The question is how do they do it and what can we learn of relevance to human obesity?

Using F344 rats, which display differential food intakes and body weight trajectories depending upon daylength, we have been exploring gene expression and other changes which underpin these responses in the brain. Our results have identified novel thyroid hormone and vitamin A signaling pathways in the hypothalamus. These are associated with extraordinary and dynamic structural/cellular re-modelling of the hypothalamus involving both cell proliferation and inflammation and which underpin the seasonal responses. These data provide new and exciting insights into how brain signaling is involved in the control of energy balance and provide a different perspective to that obtained from natural and induced gene mutation rodent models of obesity and perturbed energy balance.