Smit’s work is centered around the understanding of neuronal and synaptic (dys)function in animal models and the human postmortem brain in relation to neurological and psychiatric disease. He uses an integrated set of state-of-the-art quantitative proteomics technologies, high-content cellular assays, automated behavioral screening and chemo- and optogenetics approaches. In particular, quantitative synaptic proteomics approaches have been instrumental in the definition of the synaptic proteome, the synaptic interactome and the functional annotation of synaptic proteins as part of the international Synaptic Gene Ontologies (SynGO) consortium, which Smit coordinated with his colleague Matthijs Verhage. The SynGO platform now comprises a collection of 1,200 proteins which are literature-curated and show evidence-based synaptic localization and function. Protein-protein interaction data will be added to the platform in the coming years, as an important step towards causality modeling of the synapse.