The cellular composition of the human brain changes dynamically during development. It is composed of progenitor cells that give rise first to neurons and then to glial cells. Progenitors and differentiated cells are exposed to extracellular signals not only from the cerebrospinal fluid, the basement membrane, and the forming blood vessels, but also from their neighboring cells. Cellular cross-talk is an essential process that is influenced by several factors, including cell morphology, adhesion molecules, the local extracellular matrix, and secreted vesicles.

“To date, extracellular signals and in particular secreted vesicles have been at the center of studies of neuron-to-neuron communication. Whereas in my laboratory we are focusing on the role of extracellular signals in progenitor-to-neuron/astrocyte communication during development”, explains Cappello. “Extracellular vesicles are secreted by all cells and contain nucleic acids, proteins, and lipids that are transported from the donor cell to the recipient cell. These vesicles can be secreted locally, travel through the extracellular space, and then be internalized by different cells. They act as mediators of cell-to-cell communication and are involved in many physiological and pathological processes – including stem cell maintenance and plasticity, proliferation, apoptosis, and repair of damaged tissue.”

Extracellular vesicles have also been shown to play a role in several diseases such as stroke, Alzheimer’s and Parkinson’s diseases, and prion disease. “SyNergy provides an excellent opportunity to foster collaborations to decipher how these signals may be coordinated in human brain development and homeostasis, and whether altered cross-talks between cells may affect the proper establishment/maintenance of brain architecture affected in neurodevelopmental and neurodegenerative disorders”, concludes Cappello.