The fime around birth is accompanied by comptex behavioural, physiological and neuronal adaptafions of the maternal brain, which ensure reproductive funcfions and the mental health of the mother. Such adaptations are described at limbic, hypothalamic and pituitary levels resulting in reduced anxiety, attenuated responsiveness ofthe hypothalamic-pituitary adrenal (HPA) axis and lower neuronal reactivity to acute stressors. Mal-adaptations of these systems caused, e.g., by chronic pregnancy stress (PS), have been associated with the aetiology of postpartum anxiety and depression. Based on our preliminary results of profound PS effects on peripartum-associated emofional, neuroendocrine and neuronal adaptafions, we will study PS effects at att levels of the HPA axis and hippocampal neurogenesis, with or without therapeutic intervention by antidepressants or stress-protective neuropeptides (oxytocin, OXT; prolactin, PRL). However, despite of a higher stress vulnerability and prevalence of anxiety- and depression disorders in women, consequences of chronic stress in women or female rodents are generally understudied. Therefore, we will determine in great detail chronic psychosocial stress effects in virgin female rats inctuding emotionality, HPA axis and hippocampal neurogenesis, which will be included for comparison with peripartum animats. The experiments will be extended by the use of rats with genetic differences in anxiety- and stress-related parameters in order to determine gene x stress environment interactions shaping lactation-associated behavioural and physiological parameters.
