Age-related changes and effects of regular low-intensity exercise on gait, balance, and oxidative biomarkers in the spinal cord of Wistar rats

Whole body vibration, an alternative for exercise to improve recovery from surgery?

Although exercise is usually associated with beneficial effects on physical and mental health, patients recovering from surgery may be hampered to perform active exercise. Whole body vibration (WBV) is suggested a passive alternative for physical training. Aim of the present study was to explore the therapeutic potential of WBV compared to physical exercise during early post-surgery recovery.

Male three months old Wistar rats underwent major abdominal surgery. Starting the day after surgery, rats were subjected to either daily WBV or exercise (treadmill running) for 15 consecutive days. Control rats underwent pseudo treatment. During the first week after surgery, effects of interventions were obtained from continuous recording of hemodynamic parameters, body temperature and activity (via an implanted transducer). Behavioral tests were performed during the second post-surgical week to evaluate anxiety-like behavior, short and long-term memory functions, cognitive flexibility and motor performance. Animals were sacrificed 15 days after surgery and brain tissue was collected for analysis of hippocampal neuroinflammation and neurogenesis.

Surgery significantly impacted all parameters measured during the first post-surgery week, irrespective of the type of surgery. Effect on cognitive performance was limited to cognitive flexibility; both WBV and exercise prevented the surgery-induced decline. Exercise, but not WBV increased anxiety-like behavior and grip strength. WBV as well as exercise prevented the surgery-induced declined neurogenesis, but surgery-associated hippocampal neuroinflammation was not affected.

Our results indicated that active exercise and WBV share similar therapeutic potentials in the prevention of surgery induced decline in cognitive flexibility and hippocampal neurogenesis. In contrast to exercise, WBV did not increase anxiety-like behavior. Since neither intervention affected hippocampal neuroinflammation, other mechanisms and/or brain areas may be involved in the behavioral effects. Taken together, we conclude that WBV may provide a relevant alternative to active exercise during the early stage of post-operative recovery.

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Both whole body vibration (WBV) and running exercise restored the reduced cognitive flexibility caused by surgery.

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WBV as well as active exercise prevented surgery-induced declined neurogenesis.

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Active exercise, but not WBV, induced anxiety-like behavior after surgery.

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Neither WBV nor active exercise affected surgery-induced neuroinflammation.

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Neither WBV nor active exercise influenced hemodynamic recovery from surgery.

Chronic whole body vibration ameliorates hippocampal neuroinflammation, anxiety-like behavior, memory functions and motor performance in aged male rats dose dependently

Whole body vibration (WBV) is a form of passive exercise by the stimulation of mechanical vibration platform. WBV has been extensively investigated through clinical studies with main focus on the musculoskeletal system. However, pre-clinical data in the context of behavior, memory and motor functions with aged rodents are limited. The aim of this experiment was to investigate the dose dependent effects of a five weeks long WBV intervention with an aged animal model including anxiety-related behavior, memory and motor functions, as well as markers of (neuro)inflammation. Male Wistar rats (18 months) underwent 5 or 20 min daily vibration exposure or pseudo-treatment (i.e.: being subjected to the same environmental stimuli for 5 or 20 min, but without exposure to vibrations) 5 times per week. After 5 weeks treatment, cognitive functions, anxiety-like behavior and motor performance were evaluated. Finally, brain tissue was collected for immunohistological purposes to evaluate hippocampal (neuro)inflammation. Animals with 20 min daily session of WBV showed a decrease in their anxiety-like behavior and improvement in their spatial memory. Muscle strength in the grip hanging test was only significantly improved by 5 min daily WBV treatments, whereas motor coordination in the balance beam test was not significantly altered. Microglia activation showed a significant decrease in the CA1 and Dentate gyrus subregions by both dose of WBV. In contrast, these effects were less pronounced in the CA3 and Hilus subregions, where only 5 min dose showed a significant effect on microglia activation. Our results indicate, that WBV seems to be a comparable strategy on age-related anxiety, cognitive and motor decline, as well as alleviating age-related (neuro)inflammation.

Whole Body Vibration Improves Spatial Memory, Anxiety-Like Behavior, and Motor Performance in Aged Male and Female Rats

Aging is a progressive process leading to functional decline in many domains. Recent studies have shown that physical exercise (PE) has a positive influence on the progression of age-related functional decline, including motor and brain functions. Whole body vibration (WBV) is a form of passive stimulation by mechanical vibration platforms, which offers an alternative for PE interventions, especially for aged individuals. WBV has been demonstrated to mimic the beneficial effects of PE on the musculoskeletal system, as well on the central nervous system. However, preclinical data with aged rodents are very limited. Hence, the purpose of this experiment was to investigate the effects of a 5-week WBV intervention with an aged animal model on memory functions, anxiety-related behavior, and motor performance. The 18-month old male (N = 14) and female (N = 14) Wistar rats were divided into two groups, namely, vibration and pseudo-vibration. Animals underwent a 5-week WBV intervention protocol with low intensity (frequency of 30 Hz and amplitude of 50–200 μm) stimulation. After 5 weeks, the following cognitive and motor tests were administered: open-field, novel and spatial object recognition, grip-hanging, and balance-beam. WBV-treated rats showed a decrease in their anxiety level in the open field test compared with those in the pseudo-treated controls. In addition, WBV-treated male animals showed significantly increased rearing in the open-field test compared to their pseudo controls. Spatial memory was significantly improved by WBV treatment, whereas WBV had no effect on object memory. Regarding motor performance, both grip strength and motor coordination were improved by WBV treatment. Our results indicate that WBV seems to have comparable beneficial effects on age-related emotional, cognitive, and motor decline as what has been reported for active PE. No striking differences were found between the sexes. As such, these findings further support the idea that WBV could be considered as a useful alternative for PE in case active PE cannot be performed due to physical or mental issues.

Aspirin Exerts Neuroprotective Effects by Reversing Lipopolysaccharide-Induced Secondary Brain Injury and Inhibiting Matrix Metalloproteinase-3 Gene Expression

Objective

This study is aimed at exploring the possible neuroprotective mechanism of aspirin and the effect of bacterial endotoxin lipopolysaccharide (LPS) during cerebral ischaemia-reperfusion (CIRP) injury.

Methods

We established three animal models: the CIRP, LPS, and CIRP+LPS models. Mortality, the injured brain area, and the beam walking test were used to estimate the degree of cerebral injury among the rats. Immunohistochemistry and immunofluorescence were used to detect activated microglia, matrix metalloproteinase-3 (MMP-3), and osteopontin (OPN).

Results

The injured brain area and mortality were dramatically reduced (p < 0.01), and the beam walking test scores were elevated (p < 0.01) in the acetylsalicylic acid (ASA) group compared to the control group. The number of microglia-, MMP-3-, and OPN-positive cells also increased. Furthermore, the number of GSI-B4, OPN, and MMP-3 cells decreased in the ASA group compared to the control group. After LPS stimulation, the number of microglia reached a peak at 24 h; at 7 d, these cells disappeared. In the ASA group, the number of microglia was significantly smaller (p < 0.05), especially at 24 h (p < 0.01), compared to the LPS group. Moreover, the injured brain area and the mortality were dramatically increased and the beam walking test scores were reduced (p < 0.01) after LPS simulation following CIRP. The degree of injury in the ASA group resembled that in the control group. However, the number of MMP-3-immunoreactive neurons or microglia was significantly larger than that of the control group (p < 0.05). In the ASA group, the MMP-3 expression was also considerably decreased (p < 0.05).

Conclusions

After CIRP, microglia were rapidly activated and the expression of MMP-3 and OPN significantly increased. For rats injected with LPS at reperfusion, the injured brain area and mortality also dramatically increased and the neurologic impairment worsened. However, ASA exhibited a neuroprotective effect during CIRP injury. Furthermore, ASA can reverse LPS-induced cerebral injury and inhibit the inflammatory reaction after CIRP injury.

Aging and low-intensity exercise change oxidative biomarkers in brain regions and radiographic measures of femur of Wistar rats

We investigated changes in oxidative biomarkers in brain regions such as brainstem, cerebellum, and cerebral cortex of 3-, 6-, 18-, 24-, and 30-month-old rats. We also assessed the effects of low-intensity exercise on these biomarkers in these regions of 6-, 18-, and 24-month-old rats that started exercise on a treadmill at 3, 15, and 21 months of age, respectively. Radiographic images of the femur were taken for all rats. A total of 25 rats (age: twelve 6-, ten 18-, ten 24-, and three 30-month-old rats) were used. Lipid hydroperoxide levels increased in cerebellum at 18 months. Total antioxidant activity exhibited lowest values in brainstem at 3 months. Superoxide dismutase activity did not exhibit significant changes during aging. Total thiol content exhibited lowest values in brain regions of 24- and 30-month-old rats. Exercise reduced total thiol content in brainstem at 6 months, but no change occurred in other regions and other ages. Femur increased its length and width and cortical thickness with advancing age. No change occurred in medullary width. Radiolucency increased and sclerosis was found in cortical and medullary bone with advancing age. Exercise reduced radiolucency and medullary sclerosis. Therefore, aging differentially changed oxidative biomarkers in different brain regions and radiographic measures of the femur. Low-intensity exercise only ameliorated some radiographic measurements of femur. Since the present study possessed limitations (small number of rats per group), a beneficial effect of regular low-intensity exercise on oxidative markers in brain cannot be ruled out.

Cannabidiol improves metabolic dysfunction in middle-aged diabetic rats submitted to a chronic cerebral hypoperfusion

Cannabidiol (CBD), a compound obtained from Cannabis sativa, has wide range of therapeutic properties, including mitigation of diabetes and neurodegeneration. Cerebral ischemia and consequent learning disabilities are aggravated in elderly diabetic subjects. However, there are no studies showing the effect of CBD treatment in elderly diabetes patients suffering cerebral ischemia. The present work tested the hypothesis that CBD treatment improves metabolic dysfunctions in middle-aged diabetic rats submitted to chronic cerebral hypoperfusion. In this work, 350-day-old male Wistar streptozotocin-induced diabetic rats were used. To induce cerebral ischemia was used a chronic cerebral hypoperfusion (CCH), surgically, via the four-vessel occlusion/internal carotid artery (4-VO/ICA). Four diabetic groups were established: Non-CCH Treated Diabetic (DNT), CCH Treated Diabetic (DCT), Non-CCH Vehicle Diabetic (DNV), and CCH Vehicle Diabetic (DCV). Vehicle groups were not treated with CBD. The animals were treated during 30 days with 10 mg CBD/Kg bw/day. After treatment, the animals were euthanized, and blood levels of glucose, insulin, total cholesterol, high density lipoprotein (HDL), low density lipoprotein (LDL), triglycerides, fructosamine, aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were evaluated. DCT group presented reduction of hyperglycemia and an increase of insulinemia. Also was observed lower fructosamine, LDL, HDL, triglycerides and total cholesterol levels. AST and ALT concentration were reduced in CBD treated groups. CBD may be used as therapeutic tool to protect metabolism against injuries from diabetes aggravated by cerebral ischemia.