The study investigates the role of connexin hemichannels in intercellular calcium (Ca²⁺) signaling in astrocytes. Using patch clamp, dye flux, ATP assay, and Ca²⁺ imaging techniques, the researchers found that astrocytes exhibit low Ca²⁺-activated whole-cell currents consistent with connexin hemichannel currents, which are inhibited by flufenamic acid (FFA). Transmembrane dye flux and ATP release were also observed, indicating flux through connexin hemichannels. Mechanical stimulation potentiated dye flux and ATP release, which were inhibited by FFA and Gd³⁺. Similar effects were observed in C6 glioma cells expressing connexin43 but not in untransfected C6 cells. Quinine, a connexin hemichannel activator, evoked ATP release and Ca²⁺ signaling in astrocytes and C6 cells expressing connexin43. The propagation of intercellular Ca²⁺ waves was also potentiated by quinine and inhibited by FFA and Gd³⁺. These findings suggest that ATP release through connexin hemichannels is a novel signaling pathway for intercellular communication in astrocytes and other non-excitable cells.The study investigates the role of connexin hemichannels in intercellular calcium (Ca²⁺) signaling in astrocytes. Using patch clamp, dye flux, ATP assay, and Ca²⁺ imaging techniques, the researchers found that astrocytes exhibit low Ca²⁺-activated whole-cell currents consistent with connexin hemichannel currents, which are inhibited by flufenamic acid (FFA). Transmembrane dye flux and ATP release were also observed, indicating flux through connexin hemichannels. Mechanical stimulation potentiated dye flux and ATP release, which were inhibited by FFA and Gd³⁺. Similar effects were observed in C6 glioma cells expressing connexin43 but not in untransfected C6 cells. Quinine, a connexin hemichannel activator, evoked ATP release and Ca²⁺ signaling in astrocytes and C6 cells expressing connexin43. The propagation of intercellular Ca²⁺ waves was also potentiated by quinine and inhibited by FFA and Gd³⁺. These findings suggest that ATP release through connexin hemichannels is a novel signaling pathway for intercellular communication in astrocytes and other non-excitable cells.