Brain Responses to Intragastric Administration of a Bitter Agonist in Homeostatic and Hedonic Brain Regions

Brain Responses to Intragastric Administration of a Bitter Agonist in Homeostatic and Hedonic Brain Regions

The investigators aim to study the brain mechanisms underlying the effect of subliminal (not consciously perceived) intragastric administration of bitter tastants on hunger and food intake, which was previously found. The investigators will assess brain activation patterns after an acute intragastric administration of Quinine-hydrochloride versus saline on two different test days, and will simultaneously assess a putative role of altered gut peptide release in these effects. The hypothesis is that intragastric infusion of a bitter agonist will decrease the activity in homeostatic and hedonic brain regions and that this effect is mediated by gut peptide release.

Inclusion Criteria:

• Healthy volunteers
• Female
• N = 15
• Age 18 - 60
• Body Mass Index (BMI) of 20 - 25 kg/m
• Stable body weight for at least 3 months prior to the start of the study

Exclusion Criteria:

• Abdominal or thoracic surgery. Exception: appendectomy
• Gastrointestinal, endocrine or neurological diseases
• Cardiovascular, respiratory, renal or urinary diseases
• Hypertension
• Food or drug allergies
• Anemia
• Eating disorders and people who show abnormal eating behavior
• Depressive disorders
• Psychotic disorders
• No medication on a regular basis, expect for oral contraception
• Conditions that can interfere with functional magnetic resonance imaging (fMRI), e.g. cochlear implants, metal fragments or metal implants in the body, pacemaker, neural stimulator, …
• No history of cannabis use or any other drug of abuse for at least 12 months prior to the study
• Alcohol abuse (more than 21 units of alcohol for men, more than 14 units for woman per week)
• Dieters
• Pregnant or breastfeeding women
• Claustrophobia