TH and Alzheimer disease: Also similar to many parts of the brain, there was a greater reduction of TH+ nerve fibers in 3-month-old APP/PS1 mice compared to 3-month-old WT mice (7.43 ± 0.47 vs 5.02 ± 0.34, P = 0.0003, Fig. 7b) and in 12-month-old APP/PS1 mice compared to 12-month-old WT mice (5.9 ± 0.34 vs 2.5 ± 0.15, P < 0.0001, Fig. 7b), again suggesting a more deleterious effect of AD pathogenesis than aging on catecholaminergic degeneration.