GRM5 and Alzheimer disease: In addition to the relationships described in the primary analyses for hippocampus and entorhinal cortex, mGluR5 binding and synaptic density had a strong, positive correlation in the amygdala for the AD group (r = 0.84, p < 0.001), and a weaker non-significant correlation in the CN group (r = 0.56, p = 0.057).