Research / Forschung

Research 

The scientific focus of our Department of Behavioural and Molecular Neurobiology lies on the brain mechanisms underlying emotional and social behaviours, and stress-related adaptations - both acute and chronic, early in life or in adulthood. We are, in particular, interested in the fine-tuned involvement of neuropeptides of the brain such as oxytocin, vasopressin, corticotropin-releasing factor (CRF) and neuropeptide S in the regulation of anxiety- and depression-related behaviours, social preference, social avoidance, social fear, inter-male and abnormal aggression, and maternal and sexual behaviour in rodents. Another major research topic is related to chronic psychosocial stress, and its consequences on, for example, emotionality, the central metabotropic glutamate system, the hypothalamic-pituitary-adrenal (HPA) axis and immunological functions.

Examples of on-going research projects

1. Behavioural effects of Oxytocin

Oxytocin is a prosocial nonapeptide described to promote maternal, sexual, affiliative, and social cognitive behaviours, and to exert anxiolytic actions. These findings prompted us to monitor local release patterns of oxytocin in response to stressful or social stimuli using intracerebral microdialysis in conjunction with a sensitive radioimmunoassay. Further, we study its role in social preference versus social avoidance, and in social fear in a novel social fear-conditioning paradigm (projects Dr. Michael Lukas and Dr. David Slattery. There is a strong translational aspect, as social fear and lack of social interactions are symptoms of human social dysfunctions seen in patients suffering from autism or social anxiety disorders.

2. Cellular and molecular mechanisms of neuronal oxytocin actions

Although multiple effects of oxytocin were revealed in human and animal research, underlying receptor-mediated intraneuronal signalling cascades within brain target regions are almost unknown. Using molecular approaches, we aim to reveal molecular mechanisms of these behavioural effects studying oxytocin receptor-mediated intraneuronal signalling cascades in the hypothalamus – a key area of anxiety- and stress-regulation (projects Dr. Erwin van den Burg).

3. Neuropeptides in other social behaviours: From maternal love to sex and male aggression

Neuropeptides play a major role in various other social behaviours such as maternal behaviour, inter-male aggression or sexual behaviour. For example, we could show that, in addition to oxytocin, the related vasopressin is an important promoter of maternal care and maternal aggression studying rats selectively bred for high (HAB) versus low (LAB) innate anxiety. This project has particular clinical relevance as mal-adaptations of the brain oxytocin or vasopressin system might be related to postpartum depression often accompanied by child neglect or even infanticide (projects PD Dr. Oliver Bosch).

Moreover, aggression and violence are not only highly relevant for human societies, but interesting from the neurobiological point of view. We focus on the genetic factors, social environmental influences and resulting neuronal mechanisms shaping inter-male and abnormal aggression. For example, we could reveal a prominent role of the dopaminergic system in the nucleus accumbens shaping high and abnormal aggression in rats (project Dr. Daniela Beiderbeck). These studies are part of the Themenverbund Violence and aggression in nature and culture of the University of Regensburg, with participating scientists from 7 different faculties.

There are reciprocal interactions of the oxytocin and serotonin systems, which are relevant in the context of psychiatric diseases such as depression, anxiety disorders, schizophrenia, and sexual dysfunctions. Current treatment with serotonergic drugs may, therefore, work via the oxytocin system. We study the anatomical, pharmacological and behavioural aspects of OT/5-HT interactions using immunofluorescence, microdialysis, and psychopharmacological and behavioural approaches. In particular, we investigate male rat sexual behaviour which is known to be under both serotonergic and oxytocinergic control (Project Dr. Trynke de Jong).

4. Consequences of Chronic Psychosocial Stress

These days, we frequently use the term "stress" to describe an overload of work, or work under time pressure. However, by definition, “stress” describes the healthy response of the body to an acute stressor in order to reinstall the physiological balance (homeostasis). In contrast, in particular chronic psychosocial stress is a large burden in modern societies and a risk for various somatic (e.g. colitis, cancer) and mental (depression, burnout, hyper-anxiety) diseases. We are interested in the adaptive and/or mal-adaptive behavioural, immunological and neuroendocrine consequences of chronic stress, and the associated molecular and cellular changes. For this purpose, we chronic subordinate colony housing (CSC) paradigm (Fig). We also study genetic factors and early life experiences shaping an individual’s vulnerability versus resilience to adult chronic stress in adulthood (Projects PD Dr. Stefan Reber)

Another long-lasting research interest is related to physiological and behavioural alterations of the stress responsiveness in the peripartum period, namely in pregnancy and during lactation, which enables the healthy development of the offspring and mental health of the mother. Chronic stress in this sensible time period may prevent or reverse these important reproduction-related adaptations, and we study the underlying molecular, cellular and behavioural mechanisms, in particular mal-adaptations of the brain oxytocin system (Projects Dr. David Slattery).

The complex interactions between genes, environmental factors and adult emotionality, chronic stress vulnerability and social behaviours are shown here: