Effects of weight-bearing ladder and aerobic treadmill exercise on learning and memory ability of diabetic rats and its mechanism

Abstract

To investigate the effects of climb ladder and aerobic treadmill exercise on learning memory ability in diabetic rats and explore its possible mechanisms. Forty male rats were randomly divided into normal control group (NC), diabetic control group (DC), diabetic loading ladder group (DL) and diabetic aerobic treadmill group (DA), diabetes was induced by a single intraperitoneal injection of STZ. In the evening, the DL group were trained three cycle (10 times/cycle) with weight-bearing climbing ladder, 2 min intervals, 6 days/week, lasted for six weeks. The DA group was trained on a motor-driven treadmill at a speed of 20 m/min (0 incline), 30 min/day, 6 days/week, lasted for six weeks. Morris water maze was used to detect the learning and memory ability of rats after modeling success and after exercise intervention. After the last water maze test, the rats were killed to obtain the hippocampus. RT-QPCR was used to detect the gene expressions of brain derived neurophic factor (BDNF), tropomyosin receptor kinase B (TrkB) and cAMP-response element binding protein (CREB). Compared with NC group, the expressions of BDNF and CREB gene in hippocampus of DC group and the learning and memory ability were significantly decreased. Compared with DC group, the expression of BDNF and CREB in hippocampus of DL and DA rats was significantly up-regulated and the learning ability was significantly increased. The TrkB gene of hippocampus in DL rats was significantly up-regulated and the spatial memory ability was significantly improved. Compared with the DA group, the TRKB and CREB genes in the hippocampus of DL group were significantly up-regulated. Aerobic treadmill exercise and weight-bearing ladder exercise have a positive effect on the learning ability of diabetic rats, while the weight-bearing ladder exercise improves the memory ability of diabetic rats better than aerobic exercise. These effects may be related to the up-regulation of BDNF/TrkB/CREB signaling pathway.