Figure 2.

In vitro IP1 accumulation in mGluR5-expressing HEK293 cells is increased by quisqualic acid (QA) and decreased by mGluR5 NAMs. The group I mGluR agonist QA (black ◆) dose dependently enhanced IP3 production, resulting in increased IP1 accumulation. All tested NAMs, including the prototypical mGluR5 NAMs, 1 (red ◻) and 2 (blue △), and the novel NAMs, 7i (green ○) and 7j (purple ▽), showed dose-dependent inverse agonism, reducing IP1 accumulation in the absence of agonist. Values presented are means ± SEMs from at least three experiments.