Objective: The respiratory network is strongly modulated by neuromodulators like norepinephrine and serotonin or via metabotropic glutamate receptor activation. Since the respiratory activity generated by neurons in the preBötzinger complex (preBötC) is also maintained and stabilized by astrocytes, we addressed the effects of these neuromodulators on the astrocytic calcium signalling in ventral respiratory group. Methods: Calcium imaging experiments were performed in acutely isolated brainstem slices from mice (postnatal day 1-10) using Oregon Green 488 BAPTA-1 AM. Astrocytes were identified either by expression of red fluorescent protein in TgN (hGFAP-mRFP) mice or by their unique intracellular calcium rise after the reduction of the extracellular K+ concentration from 3 mM to 0.2 mM. Results: Astrocytes in the preBötC showed calcium rises in response to norepinephrine in a dose dependent manner. These calcium signals persisted after blockade of neuronal activity by TTX (500 nM) indicating that they were independent of neuronal activity. Similarly, activation of group 1 metabotropic glutamate receptors by dihydroxyphenylglycine (DHPG; 50 mM) also resulted in TTX-resistant calcium transients in astrocytes in the preBötC. Furthermore, application of the endoplasmic reticulum calcium pump blocker cyclopiazonic acid (CPA) prior to application of DHPG suppressed DHPG-induced calcium signals by 60%. Conclusion: Our data suggest an indirect, but yet unknown effect of the stimulatory neuromodulators via activation of astroglial calcium signals.