HTR6 and Alzheimer disease: In addition, treadmill exercise training (45 min/session, 3 sessions/week for 32 weeks) could ameliorate anxious/depressive-like behavior and attenuate fear-avoidance behavior deficits in TgF344-AD rats in the early stage of Alzheimer’s pathogenesis by increasing the expression of 5-HT and 5-HT6R in the cortex and hippocampus (Wu et al., 2020).