"Signalling at nerve cell synapses - a key determinant of all aspects of brain function - depends on the function of hundreds of synaptic proteins and their interactions. Numerous recent studies showed that a wide range of neurological and psychiatric diseases are 'synaptopathies' whose onset and progression are due to mutations of synaptic proteins and subsequent synaptic dysfunctions. EUROSPIN will pursue a multilevel systems biology approach to determine mechanistic relationships between mutations of synaptic proteins and neurological and psychiatric diseases, and to develop new diagnostic tools and therapies. Our concept is based on the current knowledge of disease genes, which we will continuously extend with new human genetic data and complement with large-scale screens of mutant mice in order to identify and characterize disease-relevant mutations in synaptic proteins and corresponding mouse models. Proteomic tools will be used to analyse the protein components of synapses, and protein interaction networks of synaptic disease gene products will be mapped systematically. In parallel, smart libraries will be employed to develop small molecules for perturbing the functions and interactions of disease gene products. Functional models of disease-relevant protein networks will be generated and used to formulate hypotheses as to how specific mutations might affect synaptic physiology and network function, and thus cause disease. These hypotheses will initially be tested in reduced systems by novel physiological and imaging methods. Well-validated disease gene products, the consequences of their dysfunction in disease, and therapeutic modifications of their dysfunction will then be studied in mouse models in vivo, applying novel electrophysiological, imaging, and behavioural techniques. The combined information obtained in the EUROSPIN program will be used for the development of new diagnostic tools and therapeutic interventions that can be tested in patients."