Figure 5. G_i/o and G_q GPCRs stimulate different signaling pathways that do not occlude.

(A and B) Scheme of experimental set-up, and astrocyte Ca²⁺ responses to ACh (left), DHPG (middle), and both simultaneously (right), showing the observed (black trace) and expected (green trace) responses. Expected response corresponds to the linear summation of the responses evoked by independent application of ACh and DHPG. (C and D) as in (A and B), but with GABA instead of DHPG. (E) Histogram of the ratio of the observed and expected Ca²⁺ responses evoked by simultaneous application of GPCR agonists in the different pharmacological conditions. Expected responses were considered the linear summation of the responses elicited by independent stimulation of the agonists. Data are represented as mean ± SEM. P < 0.001 (***).