Effects of Exercise Training on Anxious-Depressive-like Behavior in Alzheimer Rat.
Med Sci Sports Exerc. 2020 Feb 5. Epub 2020 Feb 5. PMID: 32028456
PURPOSE: This study aimed to examine the effects of treadmill training on anxious-depressive-like behaviors of transgenic Alzheimer rats in the early stage of Alzheimer's disease (AD) and provided evidence of exercise in alleviating fear-avoidance behavior deficits.
METHODS: Male 2-month-old TgF344-AD and wild-type (WT) rats were divided into WT (n = 9), AD (n = 8), and AD + treadmill exercise (Exe) groups (n = 12). After 8 months of exercise, the passive avoidance test, Barnes maze task, novel object recognition test, and object location test were used to measure learning and memory function. The open field test, elevated plus maze, sucrose preference test and forced swim test were conducted to determine the anxious-depressive-like behavior of AD rats. Immunofluorescence staining, Western blot analysis, enzyme-linked immunosorbent assay (ELISA) analysis, and related assay kits were used to measure inflammatory cytokines, oxidative stress, amyloid-beta production, and tau hyperphosphorylation.
RESULTS: Behavioral tests revealed that 12-month old animals did not show any spatial learning and memory deficits but did display anxious-depressive-like behavior (open field, Center time: P = 0.008; Center entries: P = 0.009; Line crossings: P = 0.001). However, long-term exercise significantly inhibited anxious-depressive-like behavior in AD rats (Center time: P = 0.016; Center entries: P = 0.004; Line crossings: P = 0.033). In addition, these animals displayed increased Aβ deposition, Tau hyperphosphorylation, microgliosis, inflammatory cytokines release, and oxidative damage, which were attenuated significantly by long-term exercise training.
CONCLUSION: Long-term exercise training alleviated anxious-depressive-like behavior and improved fear-avoidance behavior in transgenic AD rats, supporting exercise training as an effective approach to prevent anxiety, depression and fear-avoidance behavior deficits in the early stages of AD pathogenesis.