My interest is the impact of obesity on cognitive function. Therefore, we investigate a leptin knockout mouse model. These mice lack the protein leptin, which is responsible for the feeling of satiety. Due to their excessive feeding, leptin knockout mice gain about three times the body weight of control littermates. Since we were interested in getting insight in possible maladaptions of neuronal plasticity caused by obesity, we will focus our analysis on the hippocampus, a brain region thought to play key roles in the transition of short-term memory to long-term memory, as well as in spatial memory. Among others, we will analyze the impact of obesity on adult hippocampal neurogenesis in leptin deficient mice. Since dendritic spines represent a morphological correlate of neuronal plasticity, we will also analyze whether spine densities of hippocampal pyramidal CA1-neurons were altered in this mouse model of obesity. In addition we will investigate, whether our findings translate into behavioral abnormalities that do not result from the constrained movement as a result of their weight. Therefore, activity-independent behavioral test shall be established, to answer to what extent high body weight effects cognitive function in mice. In parallel, the department of psychiatry will perform studies with humans that help to determine which of the seen behavioral effects in the mouse mutants correlate with human behavior.

Members of my Thesis Committee:

• Prof. Dr. S. Harzsch, Institute of cytology and evolutionary biology
• Prof. Dr. O. von Bohlen und Halbach, Institute of anatomy and cell biology

Cooperation partners:

• Institut für Immunologie und Transfusionsmedizin, Abteilung Immunologie, Interimsgebäude Sauerbruchstraße DZ7, 17487 Greifswald
• Klinik und Poliklinik für Psychiatrie und Psychotherapie, Ellernholzstr. 1-2, 17475 Greifswald

Research methods

• Neuroanatomical methods (Histological and Immunhistoligical staining), microscopy (light and fluorescensmicroscopy), 3D-reconstruction neuron/dendrite/spine using Neurolucida(MicroBrightField Europe, E.K.; Matthissonstrasse 6; D-39108 Magdeburg GERMANY)
• Behavior testing (open field, dark light box, hole bord, Morris water maze)
• Molecularbiological methods (Protein extraction and western blotting)