Stephanie Kullmann

Gastspreker: Esther Speksnijder
Hypothalamic Integration Mechanisms

Spreker:
Stephanie Kulmann Prof. Dr. (Stephanie.kullmann@med.uni-tuebingen.de)
Group leader/ deputy head of Metabolic Neuroimaging at the IDM
Institute for Diabetes Research and Metabolic Diseases (IDM)
of the Helmholtz Center Munich at the University of Tübingen.
Department Internal Medicine IV University of Tübingen

Titel: Investigating hypothalamic circuits using fMRI.
Hypothalamic circuits are central to the maintenance of energy balance, homeostasis and food intake. Disruption of these functions is a mainstay of metabolic disorders and a newly recognized feature of neurodegenerative diseases. My talk will cover the neuroimaging opportunities in the study of hypothalamic circuits in primarily metabolic diseases, which affect a large and growing number of the population. Human imaging studies on the hypothalamic function are still scarce; largely owing to methodological challenges of imaging this region of the brain. Nonetheless, a handful of studies have been undertaken using blood-oxygen-level-dependent contrast (BOLD) imaging or cerebral blood flow (CBF). I will present recent findings and unpublished data evaluating the hypothalamic response to different metabolic, hormonal and nutritional states using functional MRI in humans. In a state of hunger as well as in response to sweet taste, I will show that hypothalamus fMRI signal increases, especially in persons with excessive weight. Vice versa, hypothalamic responsivity to hormonal signals, as insulin, are blunted in persons at high risk to develop type 2 diabetes and in women during the luteal phase of the menstrual cycle. Recent evidence suggests that impaired hypothalamic modulation can lead to altered peripheral metabolism and increased food craving that ultimately increases fat accumulation. I will also discuss recent findings showing that disrupted insulin signaling can be normalized by pharmacological and lifestyle interventions, which was linked to improved cognitive and metabolic functions.