Understanding how the nervous system is assembled and organized at the cellular and synaptic level is key to unlocking how the brain accomplishes its cognitive and sensorimotor functions. Work in our lab is focused on understanding the role of astrocytes, a specialized class of non-neuronal cells in the central nervous system (CNS) known as glia. Astrocytes are abundant throughout the CNS and are required for a broad range of functions including synapse formation, monitoring and modulating synaptic activity, maintenance of the blood brain barrier, as well as the cellular response to injury and disease. How astrocytes accomplish such a broad array of tasks is not well understood. In our lab, we use a combination of mouse molecular genetics, advanced imaging of fixed and living tissues by confocal and two-photon laser scanning microscopy, and molecular biology tools to address how reciprocal interactions between astrocytes and neurons shape the organization of cells and synapses in the healthy brain, as well as in the injured or diseased state.