Short bouts of mild-intensity physical exercise improve spatial learning and memory in aging rats: Involvement of hippocampal plasticity via AKT, CREB and BDNF signaling

Abstract

In the present study, we investigated whether mild-intensity physical exercise represents a successful strategy to enhance spatial learning and memory and hippocampal plasticity in aging rats, as previously described for long-term exposure to running wheel or treadmill exercise. Aging Wistar rats were submitted to short bouts (4-6 min) of exercise treadmill during five consecutive weeks. This mild-intensity exercise program increased muscle oxygen consumption by soleus and heart in aging rats and reversed age-related long-term spatial learning and memory impairments evaluated in the water maze and step-down inhibitory avoidance tasks. Remarkably, the observed cognitive-enhancing properties of short bouts of exercise were accompanied by the activation of serine/threonine protein kinase (AKT) and cAMP response element binding (CREB) pro-survival signaling that culminates in the marked increase on the brain-derived neurotrophic factor (BDNF) mRNA expression and BDNF protein levels on the hippocampus of aging rats. Altogether, these results indicate that short bouts of exercise represent a viable behavioral strategy to improve cognition and synaptic plasticity in aging rats which should be taken into account in further studies addressing the effects of physical exercise in aging subjects.

Aerobic Exercise Protects Retinal Function and Structure from Light-Induced Retinal Degeneration

“…However, animal models have also suggested potential benefits of exercise to the retina. Environmental enrichment, which includes access to voluntary running wheels, slows retinal function loss in a mouse model of retinitis pigmentosa (Barone et al, 2012). Although no attempts were made in that study to isolate the possible protective effects of aerobic exercise on retinal function in the environmental enrichment model, our results suggest that aerobic exercise could play a significant role in protecting photoreceptors.…”

“…In rodents, aerobic exercise promotes neuron survival and axon regeneration after nerve transection (Ploughman et al, 2007;Wood et al, 2012), stimulates CNS neurogenesis (van Praag et al, 1999;Vessal and Darian-Smith, 2010), and improves memory and learning (Anderson et al, 2000;Radák et al, 2001). In humans, improvements in cognitive function have been observed in Alzheimer's patients (Intlekofer and Cotman, 2013;Vreugdenhil et al, 2012), along with improvements in nonmotor function in both Parkinson's disease (Filippin et al, 2010;Cruise et al, 2011) and amyotrophic lateral sclerosis patients (McCrate and Kaspar, 2008) when exposed to varying exercise regimens.…”

Combined Ampakine and BDNF Treatments Enhance Poststroke Functional Recovery in Aged Mice via AKT-CREB Signaling

“…25 In addition, exercise has been shown to facilitate improvements in cognitive function via phosphorylation of AKT and CREB signaling and BNDF expression. [26][27][28] Based on these data, we hypothesized that blocking the combined BDNF and CX1837-induced phosphorylation of AKT using the pan-AKT inhibitor, GSK-690693, would impair the recovery trajectory.…”

Caloric restriction suppresses exercise-induced hippocampal BDNF expression in young male rats

“…First, we could not evaluate how BDNF induction by the 12-week intervention contributes to the improvement of cognitive function assessed by behavioral tests. However, increased BDNF expression was associated with improved performance on hippocampal-related cognitive tasks such as learning and memory 39) , indicating that increased BDNF due to low-intensity exercise training may improve cognitive performance in this study. Second, although we showed a correlation efficient between oxidative stress and BDNF expression in the hippocampus, we did not assess the pathway connecting them.…”