Section: New Results

Modulation of Synaptic Plasticity by Glutamatergic Gliotransmission

Participants: M. De Pittà in collaboration with N. Brunel, Dept of Neuroscience and Statistics, University of Chicago, USA.

Glutamatergic gliotransmission, that is the release of glutamate from perisynaptic astrocyte processes in an activity-dependent manner, has emerged as a potentially crucial signal-ing pathway for regulation of synaptic plasticity, yet its modes of expression and function in vivo remain unclear. We focused on two experimentally well-identified gliotransmitter patwhays: (i) modulations of synaptic release and (ii) postynaptic slow inward currents mediated by glutamate released from astrocytes, and investigate their possible functional relevance on synaptic plasticity in a biophysical model of an astrocyte-regulated synapse. Our model predicts that both pathways could profoundly affect both short-and long-term plasticity. In particular, activity-dependent glutamate release from astrocytes, could dramatically change spike-timing–dependent plasticity, turning potentiation into depression (and vice versa) for the same protocol. These results have been published in Neural plasticity [17] and in a review targetting a biologist audience in the journal Neuroscience [18].