Julia Schuller (PhD-student)

Peptidergic modulation of the nucleus accumbens in context of impulse control in a rat model for eating disorders

Binge Eating Disorder (BED) is a common pathological eating disorder in North America and Europe. People suffering from this disease experience one or more “eating attacks” per week. These attacks, so called binges, usually last up to two hours, during which diseased persons consume enormous amounts of food a healthy person could not eat. The rewarding feeling during the binges rapidly changes to feelings of shame and remorse, which is why the affected people often hide their malady from their family and friends. The binges are characterized by a loss of control and the inability to restrict food consumption. This loss is a key characteristic of BED and therefore impulse control deficits are a main comorbidity.

Studies have shown a relationship between different impulsivity traits and the formation of BED. Several neurotransmitters (like dopamine or GABA) and neuropeptides (like the group of orexins or the cocaine – and amphetamine – regulated transcript (CART)) were identified to be involved in both, feeding behaviour and BED.

Aim of this PhD project is to further elucidate neuronal mechanisms underlying BED. It focusses on the shell region of the nucleus accumbens (NAc shell) as region of the reward system of the brain that is involved in impulsivity as well as in feeding behaviour. To get insight into its role in BED, the NAc shell is target of pharmacological manipulations in trained rats. Applying a simple paradigm (5 – choice serial reaction time task), the animals are divided into a high- and low- impulsive group to further investigate a potential correlation between impulsivity traits and BED. Using an animal model for BED, the microinfusions of either CART – antibodies or an orexin 1 – receptor antagonist are hypothesized to have a differential influence on the consumption during the binges in control and experimental groups. This would point towards a specific involvement of the two neuropeptides in the NAc shell in BED against the background of impulsivity.