Resistance exercise improves hippocampus-dependent memory

It has been demonstrated that resistance exercise improves cognitive functions in humans. Thus, an animal model that mimics this phenomenon can be an important tool for studying the underlying neurophysiological mechanisms. Here, we tested if an animal model for resistance exercise was able to improve the performance in a hippocampus-dependent memory task. In addition, we also evaluated the level of insulin-like growth factor 1/insulin growth factor receptor (IGF-1/IGF-1R), which plays pleiotropic roles in the nervous system. Adult male Wistar rats were divided into three groups (N = 10 for each group): control, SHAM, and resistance exercise (RES). The RES group was submitted to 8 weeks of progressive resistance exercise in a vertical ladder apparatus, while the SHAM group was left in the same apparatus without exercising. Analysis of a cross-sectional area of the flexor digitorum longus muscle indicated that this training period was sufficient to cause muscle fiber hypertrophy. In a step-through passive avoidance task (PA), the RES group presented a longer latency than the other groups on the test day. We also observed an increase of 43 and 94% for systemic and hippocampal IGF-1 concentration, respectively, in the RES group compared to the others. A positive correlation was established between PA performance and systemic IGF-1 (r = 0.46, P < 0.05). Taken together, our data indicate that resistance exercise improves the hippocampus-dependent memory task with a concomitant increase of IGF-1 level in the rat model. This model can be further explored to better understand the effects of resistance exercise on brain functions.     

Physical exercise protocols in animal models of Alzheimer’s disease: a systematic review

Several animal studies have showed the beneficial effects of physical exercise (PE) on brain function and health. Alzheimer’s Disease (AD) is the most common type of dementia, characterized by the presence of aggregated extracellular amyloid-beta (Aβ) and neurofibrillary tangles, with progressive cognitive decline. Therapeutic approaches such as PE showed to be effective in halting AD progression. Here, we present a systematic review about PE?and?AD. The search was carried out using the PubMed and LILACS databases. The following keywords were used: Alzheimer; PE; animal model. All found studies adopted aerobic exercise training as the PE protocol (100%). We identified running on treadmill as the most commonly used PE routine (62.5%). The duration of each session, intensity, frequency, and period of training most used were 60 min/day (62.5%), moderate intensity (87.5%), 5 days/week (62.5%), and 4 (37.5%) or 12 (37.5%) weeks, respectively. The AD animal models most used were the Tg APP/PS1ΔE9 (25%), models based on i.c.v. infusion of AβOs (25%) and streptozotocin (25%). All protocols used rodents to their experiments (100%), but mice were the most common (62.5%). Finally, the main results presented in all studies were capable to reduce significantly AD consequences, such as reducing Aβ or pro-inflammatory proteins levels (100%). The lack of resistance training protocols in animal models of AD indicates a huge gap that should be investigated in future studies. We suggest that PE protocols must be adapted according to the specie, lineage and life span of the animal.

     

Effects of physical exercise on memory in type 2 diabetes: a brief review

Metabolic Brain Disease - Type 2 diabetes (T2D) is a metabolic disorder that can lead to memory impairment. T2D main features are insulin resistance and hyperglycemia. Physical exercise is a...     

The impact of resistance exercise on the cognitive function of the elderly

PURPOSE: The purpose of this study was to assess the impact of 24 wk of resistance training at two different intensities on cognitive functions in the elderly. METHODS: Sixty-two elderly individuals were randomly assigned to three groups: CONTROL (N = 23), experimental moderate (EMODERATE; N = 19), and experimental high (EHIGH; N = 20). The volunteers were assessed on physical, hemodynamic, cognitive, and mood parameters before and after the program. RESULTS: On the 1 RM test (P < 0.001), the two experimental groups performed better than the CONTROL group, but they did not show differences between themselves. The EHIGH group gained more lean mass (P = 0.05) than the CONTROL group and performed better on the following tests: digit span forward (P < 0.001), Corsi's block-tapping task backward (P = 0.001), similarities (P = 0.03), Rey-Osterrieth complex figure immediate recall (P = 0.02), Toulouse-Pieron concentration test errors (P = 0.01), SF-36 (general health) (P = 0.04), POMS (tension-anxiety, P = 0.04; depression-dejection, P = 0.03; and total mood disorder, P = 0.03). The EMODERATE group scored higher means than the CONTROL group on digit span forward (P < 0.001), Corsi's block-tapping task backward (P = 0.01), similarities (P = 0.02), Rey-Osterrieth complex figure immediate recall (P = 0.02), SF-36 (general health, P = 0.005; vitality, P = 0.006), POMS (tension-anxiety, P = 0.001; depression-dejection, P = 0.006; anger-hostility, P = 0.006; fatigue-inertia, P = 0.02; confusion-bewilderment, P = 0.02; and total mood disorder, P = 0.001). We also found that IGF-1 serum levels were higher in the experimental groups (EMODERATE, P = 0.02; EHIGH, P < 0.001). CONCLUSIONS: Moderate- and high-intensity resistance exercise programs had equally beneficial effects on cognitive functioning.