The Paris-Saclay Institute of Neuroscience (NeuroPSI) is a joint Research Unit of the Paris-Saclay University and CNRS (UMR 9197) with a staff of about 250 people. NeuroPSI is dedicated to basic Neuroscience, at all scales of analysis, from molecule to cognition and from embryo to adult. The research groups of NeuroPSI are organized into three scientific departments to study neural circuits from emergence to behavioral outputs, with different scales and different approaches.