Stimulus in the form of rotation and shaking of a platform and its effect on the formation of trabecular bone in the lumbar vertebrae of mice

FNDC5/irisin mediates the protective effects of Innovative theta-shaking exercise on mouse memory

As a passive motion and non-invasive treatment, theta-shaking exercise is considered an alternative to traditional active exercise for slowing down brain ageing. Here, we studied the influence of theta-shaking exercise on fibronectin type III domain containing 5/irisin (FNDC5/irisin) in the anterior nucleus of the thalamus, hippocampus, and medial prefrontal cortex (ATN-HPC-MPFC). Further, we assessed memory in senescence-accelerated prone mice (SAMP-10 mice) using a behavioural test to confirm the protective effect of theta-shaking exercise against age-related memory decline. SAMP-10 mice were subjected to theta-shaking exercise for 9-30 weeks. Mice then performed the T-maze test and passive avoidance task. Immunohistochemical analysis and ELISA were used to assess FNDC5/irisin, nerve growth factor (NGF), and neurotrophin 4/5 (NT4/5) expression in the ATN-HPC-MPFC. In the shaking group, FNDC5 was locally upregulated within the hippocampus and MPFC area rather than exhibiting even distribution throughout brain tissue. Irisin levels were generally higher in the control group. Meanwhile, hippocampal NGF levels were significantly higher in the shaking group, with no differences noted in neurotrophin levels. Theta-shaking preserved normal neurons in certain sub-regions. However, no beneficial changes in neuronal density were noted in the ATN. Theta-shaking exercise positively affects memory function in SAMP-10 mice. FNDC5 upregulation and higher levels of NGF, along with the potential involvement of irisin, may have contributed to the preservation of normal neuronal density in the hippocampus and MPFC subregions.

Novel shaking exercises for hippocampal and medial prefrontal cortex functioning maintain spatial working memory

INTRODUCTION

The decline in spatial working memory is one of the earliest signs of normal brain aging.

OBJECTIVE

We developed a novel physical exercise method, termed the "shaking exercise," to slow down this process.

METHODS

The experimental protocol included administering the shaking exercise for 8-32 weeks in male senescence-accelerated mouse prone 10 (SAMP-10). They were subjected to the T-maze test, followed by immunohistochemical analysis, to assess the influence of the shaking exercise on the M1 muscarinic acetylcholine receptor (CHRM1) and α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) of the dorsal hippocampus and medial prefrontal cortex (dHC-mPFC).

RESULTS

The T-maze test demonstrated that the shaking group had less hesitation in the face of selecting direction at week 24. In the immunohistochemical analysis, more CHRM1s were in the CA3 subregion and more AMPARs were in the subiculum. CHRM1s and AMPARs were maintained in the CA1 region and the mPFC. The CHRM1s seem to have a positive effect on the AMPAR in the dentate gyrus (DG) region and the CA3 region. In the CA1 region, CHRM1s were negatively correlated with AMPARs. In addition, high-density neurons were expressed in the shaking group in the upstream DG, the middle part and the distal part of CA3, the distal part of CA1, and the mPFC.

CONCLUSIONS

Our results raise the possibility that maintenance of the spatial working memory effect observed with the shaking exercise is driven in part by the uneven affection of CHRM1s and AMPARs in the dHC-mPFC circuit system and significantly maintains the neuronal expression in the dHC-mPFC.

Maintenance of the Amygdala-Hippocampal Circuit Function with Safe and Feasible Shaking Exercise Therapy in SAMP-10 Mice

INTRODUCTION

Patients with dementia show reduced adaptive, behavioral, and physiological responses to environmental threats. Physical exercise is expected to delay brain aging, maintain cognitive function and, consequently, help dementia patients face threats and protect themselves skillfully.

METHODS

To confirm this, we aimed to investigate the effects of the shaking exercise on the avoidance function in the senescence-accelerated mouse-prone strain-10 (SAMP-10) model at the behavioral and tissue levels. SAMP-10 mice were randomized into 2 groups: a control group and a shaking group. The avoidance response (latency) of the mice was evaluated using a passive avoidance task. The degree of amygdala and hippocampal aging was evaluated based on the brain morphology. Subsequently, the association between avoidance response and the degree of amygdala-hippocampal aging was evaluated.

RESULTS

Regarding the passive avoidance task, the shaking group showed a longer latency period than the control group (p < 0.05), even and low intensity staining of ubiquitinated protein, and had a higher number of and larger neurons than those of the control group. The difference between the groups was more significant in the BA region of the amygdala and the CA1 region of the hippocampus (staining degree: p < 0.05, neuron size: p < 0.01, neuron counts: p < 0.01) than in other regions.

CONCLUSIONS

The shaking exercise prevents nonfunctional protein (NFP) accumulation, neuron atrophy, and neuron loss; delays the aging of the amygdala and hippocampus; and maintains the function of the amygdala-hippocampal circuit. It thus enhances emotional processing and cognition functions, the memory of threats, the skillful confrontation of threats, and proper self-protection from danger.

A novel device to prevent osteoporosis by promoting bone metabolism using a newly developed double-loading stimulation with vibration and shaking

In Japan, 13 million people have osteoporosis, including approximately 9 hundred thousand people who are bedridden owing to bone fractures from falls. Preventing osteoporosis is considered to be an important and effective way of preventing fall-related fractures. Thus, we developed a novel method of locomotor stimulation and analyzed its effectiveness in mice. Specifically, we created a double-loading device that combines vibration and shaking stimulation. The device was used to continuously stimulate ovariectomy-induced decreased bone density mouse models 30 minutes daily for 10 weeks. We then collected femur samples, created undecalcified tissue slices, calculated parameters using bone histomorphomtry, and conducted comparative testing. BS/TV (bone surface/tissue volume), N.Oc/ES (osteoclast number/eroded surface), Oc.S/ES (osteoclast osteoid surface/eroded surface), Omt (osteoid maturation time), Tb.N (trabecular number), Mlt (mineralization lag time) < (p < 0.01), N.Ob (osteoblast number), N.Ob/TV (osteoblast number/tissue volume), sLS (single labeled suface), N.Mu.Oc/ES (multinucle osteoclast number/eroded surface), and N.Mo.Oc/ES (mononucle osteoclast number/eroded surface) (p < 0.05) were significantly higher in the stimulation group than in the non-stimulation group. In addition, BS/BV (bone surface/bone volume), Tb.Sp (trabecular separation), MAR (mineral apposition rate), Aj.Ar (adjusted apposition rate) (p < 0.01), ES (eroded surface ), ES/BS (eroded surface/bone surface), and BRs.R (bone resorption rate) (p < 0.05) were significantly lower in the stimulation group than in the non-stimulation group. These results suggest that stimulation activated osteoblasts and osteoclasts, thereby leading to highly active bone remodeling. We anticipate that bone mineralization will subsequently occur, suggesting that this stimulation technique is effective in preventing osteoporosis by alleviating sudden bone density loss.

Effectiveness of exercise-induced cytokines in alleviating arthritis symptoms in arthritis model mice

Recently, health awareness in Japan has been increasing and active exercise is now recommended to prevent lifestyle-related diseases. Cytokine activities have many positive effects in maintaining the health of a number of organs in the body. Myokines are cytokines secreted by skeletal muscles in response to exercise stimulation, and have recently generated much attention. Around 700,000 patients in Japan suffer from rheumatoid arthritis, making it the most prevalent autoimmune disease that requires active prevention and treatment. In the present study, a mouse model of spontaneous arthritis (SKG/Jcl) was subjected to continuous exercise stimulation, starting before the disease onset, to examine the effects of anti-inflammatory and inflammatory cytokine secretion on arthritis. For this stimulation, we developed a device that combines shaking and vibration. The results revealed that exercise stimulation delayed the onset of arthritis and slowed its progression. Thickened articular cartilage and multiple aggregates of chondrocytes were also observed. Further, exercise stimulation increased the expression of IL-6, IL-10, and IL-15, and inhibited TNF-α expression. From these results, we infer that the anti-inflammatory effects of IL-6 and IL-10, which showed increased expression upon exercise stimulation, inhibited the inflammatory activity of TNF-α and possibly delayed the onset of arthritis and slowed its progression. Novel methods for preventing and treating arthritis under clinical settings can be developed on the basis of these findings.