This study investigates how local neurotransmitter inputs are encoded by cortical astrocyte networks. Using ex vivo and in vivo two-photon imaging, researchers found that brief, subcellular inputs of GABA and glutamate lead to widespread, long-lasting astrocyte calcium (Ca²⁺) responses. They observed that propagative Ca²⁺ activity differentiates astrocyte network responses to these two neurotransmitters, suggesting that astrocytes may influence future inputs. The results demonstrate that local, transient neurotransmitter inputs are encoded by broad cortical astrocyte networks over a minutes-long time course, contributing to accumulating evidence that substantial astrocyte-neuron communication occurs across slow, network-level spatiotemporal scales. The study also shows that astrocyte Ca²⁺ activity can be highly compartmentalized, and that spatiotemporally restricted NT release can drive Ca²⁺ activity in subcellular compartments extending beyond the stimulated region. Furthermore, the study found that astrocyte networks respond to subcellular NTs, with network-level responses to glutamate and GABA being spatially non-overlapping. Propagative activity distinguishes astrocyte network responses to GABA and glutamate, indicating that these neurotransmitters are differentially encoded at the network level. The study also highlights the role of gap junctions in facilitating network-level Ca²⁺ increases following NT release. These findings provide new insights into the mechanisms underlying astrocyte-neuron communication and the role of astrocyte networks in modulating neuronal activity.This study investigates how local neurotransmitter inputs are encoded by cortical astrocyte networks. Using ex vivo and in vivo two-photon imaging, researchers found that brief, subcellular inputs of GABA and glutamate lead to widespread, long-lasting astrocyte calcium (Ca²⁺) responses. They observed that propagative Ca²⁺ activity differentiates astrocyte network responses to these two neurotransmitters, suggesting that astrocytes may influence future inputs. The results demonstrate that local, transient neurotransmitter inputs are encoded by broad cortical astrocyte networks over a minutes-long time course, contributing to accumulating evidence that substantial astrocyte-neuron communication occurs across slow, network-level spatiotemporal scales. The study also shows that astrocyte Ca²⁺ activity can be highly compartmentalized, and that spatiotemporally restricted NT release can drive Ca²⁺ activity in subcellular compartments extending beyond the stimulated region. Furthermore, the study found that astrocyte networks respond to subcellular NTs, with network-level responses to glutamate and GABA being spatially non-overlapping. Propagative activity distinguishes astrocyte network responses to GABA and glutamate, indicating that these neurotransmitters are differentially encoded at the network level. The study also highlights the role of gap junctions in facilitating network-level Ca²⁺ increases following NT release. These findings provide new insights into the mechanisms underlying astrocyte-neuron communication and the role of astrocyte networks in modulating neuronal activity.