GRM5 and early-onset autosomal dominant Alzheimer disease: Although the striatum is not widelystudied in these mice, striatal deposits of Abeta are observed with aging in thesemice [37], and PET imagingrevealed reduced levels of D2 receptor [76] and mGluR5 [77] in striatum in 9m-old 5xFAD TG mice.Intriguingly, patients with early-onset (63±4 yrs) Alzheimer’s disease and patientswith AD (77±7yrs) show volume changes in dorsal striatum, specifically putamen[78, 79], which correlated withcognitive impairment [78].Moreover, greater amyloid load in anterior and posterior putamen correlated withgreater frailty in the elderly [80].