Astrocyte-based mechanism of working memory (WM). A Simulated firing activity of a cortical neuron before, during and after the presentation of a stimulatory cue (purple bar). B The same cue induces persistent firing activity in presence of astrocyte-mediated synaptic facilitation for more than 10 seconds (red shade). C Astrocyte-mediated facilitation results in bistability of synaptic release. D Synaptic release enhanced by the astrocyte may outlast the stimulatory cue as long as the astrocyte is kept active by the very synaptic stimuli impinging on the astrocyte. E The resulting neuronal firing statistics is more irregular in presence of the astrocyte, as marked by (F) a coefficient of variation (CV) larger than 1 after presentation of the cue (purple shade).