Ryu Group We are interested in understanding molecular and cellular mechanisms by which prolonged or severe exposure to stress hormones lead to behavioural and physiological dysfunctions using zebrafish as a model system. Our research focuses on the key stress hormones produced by our body’s main stress response system, the Hypothalamo-Pituitary-Adrenal (HPA) axis. The HPA axis coordinates diverse aspects of stress response in all vertebrates and the hormones produced by the HPA axis are remarkably conserved throughout vertebrate kingdom. Strikingly, while critical for the survival and coping capacity of the animal in fluctuating environment, the prolonged exposure to the HPA axis hormones is harmful and the dysregulation of the HPA axis is strongly implicated in a number of stress-induced disorders in humans including depression and anxiety disorders. Our lab has successfully applied advanced techniques to establish zebrafish as a model organism with which to study the stress response and HPA axis function. As a part of this effort we have developed a method that allows modulation of the HPA axis hormone levels at will in a living animal. Using such manipulations combined with robust behavioural studies and comprehensive molecular and cellular analyses, our primary goal is to identify hitherto unknown mechanisms that mediate stress hormone’s striking control of animal behaviour. Given the high degree of conservation of the stress system throughout vertebrates, the mechanistic insights we gain in zebrafish will be invaluable for understanding human stress biology as well. Recognising the potential for more sophisticated and specific medical interventions in the areas of depression and other stress-induced disorders our work is designed to harness the advantages for high-throughput analysis opportunities that zebrafish offers. To this end another major goal is to screen for novel molecules that could ameliorate detrimental effects of stress as potential new therapeutic avenues for depression and other stress-induced disorders. Current research projects address following questions: How does stress regulate neurogenesis and brain development? What are the long lasting molecular alterations induced by stress exposure and how they affect adult functions? Can we use our zebrafish stress model to identify new therapeutic targets of psychiatric diseases? PhD Opportunities LSI-funded PhD Studentship: Supervisors: Prof Soojin Ryu and Prof Steve West “Molecular mechanism underlying stress induced brain changes”