However, one study utilizing 3XTg-AD mice, which exhibit plaque pathology and tau pathology at later stages, showed that 9 months of exercise increased hippocampal microglial hypertrophy (microglia surface, volume and somata volume) (Rodríguez et al., 2015), indicating prolonged exercise may have differential regulatory effects compared to exercise of shorter durations. This evidence concerns the gene MAPT and Alzheimer disease.