Marieke seeks to understand the molecular mechanism underlying STXBP1 function and malfunction in healthy and patient-derived synapses -the contact points between neurons -. Her interest in STXBP1 is fueled by its essential but enigmatic role in synaptic transmission, the mechanism by which brain cells communicate and compute information. To study the effect of STXBP1 mutations found in patients as well as mutations designed to disrupt a specific function of STXBP1, like a modification site or protein-protein interaction site, she performs (single-cell) recordings of synaptic transmission in cultured mouse and human neurons carrying these mutations. The ultimate goal is to obtain a better understanding of STXBP1 encephalopathies, which could facilitate the discovery of effective treatments.