Effects of psychosocial stress on the behavior of S100B transgenic mice

The functional significance of the astroglial Ca²⁺-binding protein S100B is only poorly understood. It seems to play a role in the development and maintenance of the CNS being involved in synaptogenesis, dendritic development, and apoptosis and having a specific role as neurotrophic factor for serotonergic neurons. Elevated levels of S100B were found in psychiatric disorders such as depression and schizophrenia. It is not clear whether they are a causal factor for their development or if they are a consequence of pathophysiological states mediating protective or compensatory function. The aim of this study was to elucidate whether elevated levels of S100B are able to stabilize the behavior of mice raised under stressful conditions. During adolescence wild type and S100B transgenic mice were either housed under stable or unstable social conditions. S100B transgenic mice showed a locomotor hyperactivity in the open field test independent of the housing condition. Regarding the time in the center of the open field there was no difference between mice of both genotypes from the stable housing condition. Wild type mice from the unstable housing condition, however, showed a significantly reduced time in the center while S100B transgenic mice did not change their behavior in the unstable condition. Results of further behavioral paradigms will be presented and the role of S100B for behavior and neuroplasticity will be discussed.