How astrocytic ATP shapes neuronal activity and brain circuits

Astrocytes play a key role in processing information at syn-apses, by controlling synapse formation, modulating synapse strength and terminating neurotransmitter action. They release ATP to shape brain activity but it is unclear how, as astrocyte processes contact many targets and ATP-mediated effects are diverse and numerous. Here, I review recent studies showing how astrocytic ATP modulates cellular mechanisms in nearby neurons and glia in the grey and white matter, how it affects signal transmission in these areas, and how it modulates behavioural outputs. I attempt to provide a flowchart of astro-cytic ATP signalling, showing that it tends to inhibit neural cir-cuits to match energy demands.