It is intriguing how tightly-orchestrated neuronal networks fulfil, what we are appreciating as our mind and what ultimately helps us to define our personality. It is one of our most valuable skills that defines mankind, the ability to create new thoughts and learn from experience. From this it becomes clear that diseases of the central nervous system can present a tremendous burden for individuals and their families. Our group wants to understand the mechanisms of central nervous system (CNS) diseases and their effect on natural processing of information and cognitive processes. My group focuses on two main research questions: (1) We investigate neuronal ensembles and circuits involved in spatial and social cognition to decipher their role for behaviour and their impairments in the context of neurodegenerative and neuropsychiatric diseases. (2) We further aim at deciphering the interactions of tumors of the central nervous system with their microenvironment, to identify routes of communication and thus novel treatment strategies. We are using two-photon in vivo microscopy and neuronal manipulation techniques in transgenic mice to investigate structural and functional properties of brain regions in health and disease.