Astrocyte Ca²⁺ signalling has been proposed to link neuronal information in different spatial–temporal dimensions to achieve a higher level of brain integration. However, some discrepancies in the results of recent studies challenge this view and highlight key insufficiencies in our current understanding. In parallel, new experimental approaches that enable the study of astrocyte physiology at higher spatial–temporal resolution in intact brain preparations are beginning to reveal an unexpected level of compartmentalization and sophistication in astrocytic Ca²⁺ dynamics. This newly revealed complexity needs to be attentively considered in order to understand how astrocytes may contribute to brain information processing.