Glia, an active synaptic partner : from physiology to neurodegeneration
Over the past fifteen years, an increasing number of observations have progressively modified the classical view according to which glial cells are support cells in the brain, assuring optimal functioning of neurons but with no direct role in the neuronal network activity and, ultimately, in the performance of the brain. The recognition that astrocytes, the preponderant glial cell type in the brain, possess active properties, e.g. the competence for regulated release of "gliotransmitters", including glutamate, has opened the way to a fully new understanding of the role of astrocytes. Today astrocytes are envisaged as local communication elements of the brain, able to generate a variety of regulatory signals and to bridge structures (from neuronal to vascular) and networks otherwise disconnected from each other, thus playing specific and essential roles both in physiology and in an increasing number of diseases. Our lab has provided some of the seminal evidence concerning the active communication properties of astrocytes and their contribution to normal and pathological brain processes (see selected publications). Work in the lab currently focuses on: 1. the role of bidirectional communication between synapses and astrocytes in synaptic physiology; 2. the structural-functional basis of the astrocyte-synapse cross-talks; 3. the role of an altered synapse-astrocyte partnership in the progression of brain pathologies (notably, in Alzheimer’s disease and Amyotrophic Lateral Sclerosis). We mostly utilize functional approaches, combining patch-clamp electrophysiology and dynamic imaging, including two-photon microscopy, in acute brain slices and in vivo, as well as morphological imaging and immunochemistry at the optical and electron microscopic level.