Human brain development is a protracted process that arguably extents throughout the whole lifespan. It is therefore fundamental to understand how the external environment can affect brain development and the acquisition of adult function. Any developmental insults to these processes can result in the onset of neurodevelopmental disorders or the formation of brain neoplasms. Our laboratory focuses on understanding how intrinsic and extrinsic factors mediate the development and refinement of brain circuits. In particular, we focus our attention on one of the major source of extrinsic signals, the choroid plexus (CP). The choroid plexus is an unique interface between brain, blood and cerebrospinal fluid (CFS). We employ biochemical, genetic, molecular, anatomical and behavioral approaches to study the choroid plexus instructive signals and how they influence the cortical circuit development and plasticity. Furthermore, our group uses animal models of neurodevelopmental disorders and brain neoplasm, to study the possible contribution of CP-CSF cues to the pathogenesis of the respective human diseases.