Astrocytes play a major role in modulating neuronal communication in the brain,  and one of their functions is to clear glutamate after synaptic release via glutamate transporters. Sleep/wake states are regulated by the interaction of sleep/wake promoting neurons that are widely distributed in the brain; however,  the role of astrocytes in regulating these neurons is only beginning to be understood. Our recent findings show that glial glutamate transporter 1 (GLT1) exhibits sleep history-dependent,  dynamic and opposite changes in its perisomatic localization with wake-promoting orexin (ORX) and sleep-promoting melanin concentrating hormone (MCH) neurons. These GLT1 apposition changes are accompanied by modulation of excitatory transmission to ORX and MCH neurons with distinct mechanisms. This GLT1-mediated synaptic plasticity may represent a novel homeostatic mechanism for regulating sleep/wake behaviour.