LSA Fellows 1

Steroid hormones are not only involved in the regulation of sex specific development of organisms but have also short- and long-term effects on behavioral states like motivation, emotion and aggression as well as learning and memory. Behavioral modulation is realized by ligand activated cell membrane bound and cytosolic receptors which are present in neurons in a variety of brain regions. These receptors differently, genomically and non-genomically, effect intracellular signalling cascades and synaptic plasticity, commonly considered as cellular correlates of learning and memory. The role of stress hormones and their receptors in these processes are much better studied as that of sex hormones. Although the entire enzymatic machinery for the local production of estradiol and the respective receptors are present in male brains, little is known about their functions in behavioral and cognitive regulation. Therefore, we investigate these functions in male rats from the cellular to the behavioral level. The estrogen receptor β (ERβ) is mainly involved in the processing of emotional information, whereas the estrogen receptor α (ERα) plays a role in the regulation of motivation during learning tasks. Further, the results point to a mutual interaction of stress and sex hormone receptors that, in a network like manner, regulate and integrate behavioral states in order to facilitate learning and memory. The research contributes to the understanding of age dependent decline of cognitive functions as well as to the mechanims of posttraumatic stress disorders.