GRM1 and Anxiety: The Homer2AA/AA mutation also prevents activity-depending interactions with other postsynaptic density proteins, including drebrin and mGlu1 (Guo et al., 2015), and both of these interactors have been implicated in anxiety-like behavior (Spooren et al., 2010; Peterlik et al., 2016; Milanovic et al., 2017).