Neurocentre Magendie, Bordeaux Neurocampus, CNRS, France
Regulation of NMDA receptor activity by astrocytes
Understanding the properties of NMDARs and their regulation by the local environment is of paramount importance for the sake of our central nervous system. The possibility that the glycine-site of NMDARs could represent an important pathway to regulate NMDAR activity was disregarded for a long time because based on the belief that this site was fully saturated by ambient glycine. We now know that glycine is not the only endogenous co-agonist of NMDARs and that both glycine and D-serine can differentially regulate the activity of these glutamatergic receptors. We will here review our latest results describing the key roles played by astroglial IP3Receptors in providing D-serine at excitatory synapses. The impact of these processes on synaptic plasticity will also be presented.
Stéphane Oliet is a neurophysiologist who is investigating neuron-glia interactions in the healthy and diseased brain. He received his PhD from McGill University and was trained as a postodoctoral fellow at UCSF. He was recruited at the CNRS as a permanent scientist in 1997. He is presently serving as the Director of the Neurocentre Magendie in Bordeaux. His work has contributed to the emerging concept of the tripartite synapse that considers astrocytes as active players of cerebral communication. In particular, he showed that the astrocytic environment of neurons and synapses plays a key role in shaping excitation through glutamate uptake. He also characterized glia-derived D-serine as an essential component of NMDA receptor activation, a mechanism by which astrocytes regulate synaptic plasticity and memory.