Voluntary resistance running with short distance enhances spatial memory related to hippocampal BDNF signaling

Abstract

Although voluntary running has beneficial effects on hippocampal cognitive functions if done abundantly, it is still uncertain whether resistance running would be the same. For this purpose, voluntary resistance wheel running (RWR) with a load is a suitable model, since it allows increased work levels and resultant muscular adaptation in fast-twitch muscle. Here, we examined whether RWR would have potential effects on hippocampal cognitive functions with enhanced hippocampal brain-derived neurotrophic factor (BDNF), as does wheel running without a load (WR). Ten-week-old male Wistar rats were assigned randomly to sedentary (Sed), WR, and RWR (to a maximum load of 30% of body weight) groups for 4 wk. We found that in RWR, work levels increased with load, but running distance decreased by about half, which elicited muscular adaptation for fast-twitch plantaris muscle without causing any negative stress effects. Both RWR and WR led to improved spatial learning and memory as well as gene expressions of hippocampal BDNF signaling-related molecules. RWR increased hippocampal BDNF, tyrosine-related kinase B (TrkB), and cAMP response element-binding (CREB) protein levels, whereas WR increased only BDNF. With both exercise groups, there were correlations between spatial memory and BDNF protein (r = 0.41), p-CREB protein (r = 0.44), and work levels (r = 0.77). These results suggest that RWR plays a beneficial role in hippocampus-related cognitive functions associated with hippocampal BDNF signaling, even with short distances, and that work levels rather than running distance are more determinant of exercise-induced beneficial effects in wheel running with and without a load.

Exercise-induced improvement in cognitive performance after fimbria-fornix transection depends on the timing of exercise administration

“…Greenwood et al (2012) showed that running distances increase steadily over time, peak in week 4 and plateau afterwards. Comparing our results to other studies using voluntary exercise, the running distances in our study are comparable to those of Ke et al (2011) and Lee et al (2012). However, compared to those of Griesbach et al (2004b), Hayes et al (2008), Kinni et al (2011) andYau et al (2012), both intensity and distance of our animals are at the lower end.…”

Brain Glycogen Decreases During Intense Exercise Without Hypoglycemia: The Possible Involvement of Serotonin

“…In addition, it has been recently reported that the hippocampal lactate derived from glycogen acts to retain memory function, not only as an energy source, but also as a neuromodulator that increases synaptic plasticity [26,27,46]. Indeed, we have reported that a model of chronic high-intensity intermittent exercise using voluntary wheel running enhances the memory function associated with hippocampal structural changes [47,48]. In the present study, we employed a high-intensity intermittent swimming rat as an intense exercise model and found a possible involvement of serotonin in hippocampal glycogenolysis with high-intensity intermittent exercise.…”

Exercise Enhances the Behavioral Responses to Acute Stress in an Animal Model of PTSD

“…Kozlovksy et al (23) have reported that PTSD-like behavioral responses are associated with a down-regulation of BDNF mRNA, suggesting that individuals who are experiencing extreme behavioral responses to stress may have an impaired synaptic stabilization and increased sensitivity to an extreme stress response. Exercise has been shown to increase BDNF concentrations (17,24) and has also been suggested to be a mechanism for the depression-relieving effects of exercise (26).…”