MAPT and Alzheimer disease: Regarding mitochondria and glutamate, we have previously demonstrated that deficits of glutamatergic transmission and mitochondrial dysfunction coexist in the FC and HIPP of 18-month-old 3 × Tg-AD mice, which show a substantial number of amyloid plaques and tau pathology; the HIPP was the most affected area at that age (Cassano et al., 2012).