Otani S.,Ryotokuji University |
Otani S.,Juntendo University |
Bai J.,Juntendo University |
Blot K.,University Paris - Sud
Neuroscience Bulletin | Year: 2015
The prefrontal cortex (PFC) is thought to store the traces for a type of long-term memory — the abstract memory that determines the temporal structure of behavior often termed a “rule” or “strategy”. Long-term synaptic plasticity might serve as an underlying cellular mechanism for this type of memory. We therefore studied the induction of synaptic plasticity in rat PFC neurons, maintained in vitro, with special emphasis on the functionally important neuromodulator dopamine. First, the induction of long-term potentiation (LTP) was facilitated in the presence of tonic/background dopamine in the bath, and the dose-dependency of this background dopamine followed an “inverted-U” function, where too high or too low dopamine levels could not facilitate LTP. Second, the induction of long-term depression (LTD) by low-frequency stimuli appeared to be independent of background dopamine, but required endogenous, phasically-released dopamine during the stimuli. Blockade of dopamine receptors during the stimuli and exaggeration of the effect of this endogenously-released dopamine by inhibition of dopamine transporter activity both blocked LTD. Thus, LTD induction also followed an inverted-U function in its dopamine-dependency. We conclude that PFC synaptic plasticity is powerfully modulated by dopamine through inverted-U-shaped dose-dependency. © 2015, Shanghai Institutes for Biological Sciences, CAS and Springer-Verlag Berlin Heidelberg.
Nakazawa A.,Ryotokuji University |
Nakamura K.,Niigata University |
Kitamura K.,Niigata University |
Yoshizawa Y.,Niigata Council of Institutions for the Elderly
Environmental Health and Preventive Medicine | Year: 2013
Background: The purpose of this study is to assess the association between body mass index (BMI) and mortality among nursing home residents in Japan. Methods: A one-year prospective cohort study was conducted with 8,510 elderly individuals across 140 nursing homes. Baseline measurements included age, sex, height, weight, BMI, activities of daily living (ADL) (Barthel Index), and degree of dementia. Information regarding dates of discharge and mortality were also obtained to calculate person-years. Cox's proportional hazards model was used to estimate hazard ratios. Results: Mean age and BMI were 84.3 [standard deviation (SD) 8.1] years and 20.6 (SD 3.8) kg/m2, respectively. Hazard ratios of mortality adjusted for sex, age, ADL, degree of dementia, and type of home were 2.4 [95 % confidence interval (CI): 1.9-3.1] for the 1st quintile of BMI (<17.3 kg/m2), 1.7 (95 % CI: 1.3-2.3) for the 2nd quintile (17.3-19.2 kg/m2), 1.5 (95 % CI: 1.2-2.0) for the 3rd quintile (19.3-21.1 kg/m2), and 1.2 (95 % CI: 0.9-1.6) for the 4th quintile (21.2-23.5 kg/m2) (P for trend <0.001), compared with the reference 5th quintile (23.6≤ kg/m2). Conclusions: There was a clear inverse dose-dependent relationship between BMI and mortality. Future studies should be conducted to determine the effects of nutritional intervention on mortality in institutionalized elderly adults. © 2013 The Japanese Society for Hygiene.
Miyashita K.,Chubu University |
Kobayashi H.,Nihon Fukushi University |
Koshida S.,Ryotokuji University |
Urabe Y.,Hiroshima University
American Journal of Sports Medicine | Year: 2010
Background: Because a majority of throwing injuries occur near the maximum external rotation (MER) of the throwing shoulder, sports medicine practitioners and researchers have paid special attention to the shoulder kinematics at the MER in throwing. However, little is known about the individual kinematics of the glenohumeral, scapulothoracic, and thoracic joints at the MER. Purpose: To demonstrate the glenohumeral, scapulothoracic, and thoracic joint movements and their contribution to the MER in throwing for baseball players. Study Design: Descriptive laboratory study. Methods: We collected throwing motion data for 20 collegiate baseball players by using 3 high-speed cameras and established 3-dimensional coordinates of each landmark with a direct linear translation method. We then obtained the MER of the shoulder complex, the external rotation angle of the glenohumeral joint, the posterior tipping angle of the scapula, and the thoracic extension angles at the MER in throwing. Results: The mean (± standard deviation) value of the MER was 144.2° ± 11.0°. The mean (± standard deviation) values of the glenohumeral external rotation, the scapular posterior tipping, and the thoracic extension angles at the MER were 105.7° ± 15.5°, 23.5° ± 13.9°, and 8.9° ± 7.3°, respectively. Conclusion: Our results indicate that not only the glenohumeral joint movement but also the scapular and thoracic movements make major contributions to the MER angle. Clinical Relevance: To better understand the pathomechanics of the shoulder complex in throwing, we need to take into account the individual contributions of the glenohumeral, scapulothoracic, and thoracic extension movements to the MER.
Koshida S.,Ryotokuji University |
Deguchi T.,Hiroshima University |
Miyashita K.,Chubu University |
Urabe Y.,Hiroshima University
British Journal of Sports Medicine | Year: 2010
Background: Although high prevalence of anterior cruciate ligament injuries (ACL) in judokas has been reported, there has been very little research concerning events preceding the injury. Objective: To determine the common situations and mechanisms of ACL injury in judo. Methods: A total of 43 cases of ACL injuries that had occurred during judo competition or practice were investigated, using questionnaires with interviews conducted by a single certified athletic trainer who has 20 years of judo experience to obtain information regarding the situation and mechanism in which the ACL injury occurred. Results: The number of ACL injuries when the participant's grip style was different from the style of the opponent (ie, kenka-yotsu style) (28 cases) was significantly greater than when the participant's grip style was the same as that of the opponent (ie, ai-yotsu style) (15 cases; p,<.001). The number of ACL injuries was significantly higher when the participant was attacked by the opponent than when counterattacked or when attempting the attack (p,<.001). In addition, being attacked with osoto-gari was revealed as the leading cause of ACL injury incidence among the participants (16.8%). Conclusions: Grip style may be associated with ACL injury occurrence in judo. In addition, direct contact due to the opponent's attack may be a common mechanism for ACL injuries in judo.
Blot K.,University Pierre and Marie Curie |
Bai J.,University Pierre and Marie Curie |
Otani S.,University Pierre and Marie Curie |
Otani S.,Ryotokuji University
Journal of Physiology Paris | Year: 2013
Schizophrenia affects about 1% of the world population and is a major socio-economical problem in ours societies. Cognitive symptoms are particularly resistant to current treatments and are believed to be closely related to an altered function of prefrontal cortex (PFC). Particularly, abnormalities in the plasticity processes in the PFC are a candidate mechanism underlying cognitive symptoms, and the recent evidences in patients are in line with this hypothesis. Animal pharmacological models of cognitive symptoms, notably with non-competitive NMDA receptor antagonists such as MK-801, are commonly used to investigate the underlying cellular and molecular mechanisms of schizophrenia. However, it is still unknown whether in these animal models, impairments in plasticity of PFC neurons are present. In this article, we briefly summarize the current knowledge on the effect of non-competitive NMDA receptor antagonist MK-801 on medial PFC (mPFC) neuronal activity and then introduce a form of plasticity found after acute exposure to MK-801, which was accompanied by cognitive deficits. These observations suggest a potential correlation between cognitive deficits and the aberrant plasticity in the mPFC in the animal model of schizophrenia. © 2013 Elsevier Ltd.
Ryotokuji K.,Ryotokuji University |
Ishimaru K.,Ryotokuji University |
Kihara K.,Ryotokuji University |
Namiki Y.,Ryotokuji University |
Hozumi N.,Ryotokuji University
Laser Therapy | Year: 2013
Background and aims: This study was aimed at the development of a novel noninvasive treatment system, "pinpoint plantar long-wavelength infrared light irradiation (PP-LILI)", which may be able to relieve mental stress and normalize blood glucose level via the reduction of stress hormones in type 2 (non-insulin-dependent) diabetes mellitus (DM) patients. Materials (Subjects) and methods: Based on this hypothesis, the present study was undertaken to examine effects of PP-LILI on stress hormones (ACTH and cortisol), blood glucose, HbA1c, and insulin levels in 10 patients with type 2 DM. Each patient received PP-LILI of the foot for 15 minutes once weekly using a stress free apparatus (infrared wavelength, 9,000-12,000 nm/power 30 mW). Results: In response to this therapy, ACTH (P<0.01) and cortisol (P<0.05) levels decreased significantly. Fasting blood glucose (P<0.05) and insulin (P<0.05) levels also decreased significantly along with a tendency for HbA1c to decrease. Conclusions: The present data raise the possibility that PP-LILI can normalize blood glucose levels by reducing stress hormones such as cortisol, which aggravate DM, and by improving insulin sensitivity, thereby contributing to prevention and treatment of DM. © 2013 JMLL, Tokyo, Japan.
Kawasaki T.,Ryotokuji University |
Kawasaki T.,Tokyo Metroplitan University |
Higuchi T.,Tokyo Metroplitan University
Journal of Motor Behavior | Year: 2016
In a study on postural stability, the authors examined whether the effects of mental rotation (MR) intervention using a foot stimulus would last for a relatively long time (up to 60 min). The participants performed a randomly assigned MR task (using foot stimuli, hand stimuli, or non–body-related stimuli [car]) for 10 min. The amount of body sway during unipedal standing was measured immediately after the intervention and 10, 30, and 60 min after the intervention. Results showed that MR intervention using foot stimuli was more effective than that using hand or car stimuli. This suggests that foot stimuli, rather than body-related stimuli, would be advantageous for the intervention. The results show that beneficial effects were observed 60 min after the intervention; this indicates that the effects of the foot MR were unlikely to be explained on the basis of enhanced corticospinal excitability involving motor execution. The authors discuss a potential explanation for the effects and application of the MR task in a clinical setting. Copyright © 2016 Taylor & Francis Group, LLC
Matsuura H.,Ryotokuji University
International Journal of Innovative Computing, Information and Control | Year: 2016
We have proposed the method of the neural network based on quantum theory (wave equation and path integrals) of polaritons, and made some relation’s tools and descriptions for calculations for arbitrary neural circuits developed. The most important difference between the common (classical) neural network and quantum one existed in whether there were interferences between both systems. The quantum system had essentially many interferences’ relationships in its system, and so its probability was related to the probability amplitude, wave functions and propagators, which were commonly complex functions. On the other hand, the classical probability never contained any interferences since it had in the real number field. And concretely we showed how those quantum methods, whose system contained much interference, were applied to the Bayes’ theory, entropy of information theory, and the two-step neural network of multi channels. And we found that our quantum neural network and polariton’s model were connected with the common quantum information theory, classical neural system and information theory, and quantum network contained many branches of soft science. Moreover, when we attempt to practice that calculation on classical fuzzy probability and quantum amplitude, we immediately find that fuzzy probability is equivalent to Choquet integral. However, we recognize the difference between Choquet integral and path integral. As Choquet integral is always real number, but quantum integral means complex number. Thus, Choquet integral has sometimes divergence of integral values in spite of finite integral value of quantum computation. Thus, we showed that our methods were related to various areas as applications of fuzzy controls, classical neural systems, the classical information theory and so on. © 2016, IJICIC Editorial Office. All rights reserved.
Koshida S.,Ryotokuji University |
Matsuda T.,Ryotokuji University |
Kawada K.,Ryotokuji University
Journal of Sports Medicine and Physical Fitness | Year: 2011
Aim. The aim of this study was to demonstrate the kinematics and kinetics of the lower extremity during the kendo strikethrust motion in experienced kendo athletes. Methods. Fifteen experienced kendo athletes (age 20.4±1.2 years; height 171.5±4 cm; weight 73.9±9.1 kg; the kendo experience 11.1±3.1 years) volunteered to participate in the study. The three-dimensional kinematic and kinetic data was collected by the motion analysis system with eight cameras and with a force platform. We instructed the participants to perform three sets of kendo motion at the distances of 1.8 m, 2 m, and 2.2 m to the target. We then obtained the joint kinematic and kinetic data of the ankle dorsiflexion-planterflexion, foot pronation-supination, knee flexion-extension, and hip flexion-extension during the single support phase. The peak foot pronation angle and the range of motion (ROM) of foot pronation were also calculated. Results. The result demonstrated the high intra-subject repeatability of the joint angle and the torque curve of the left lower extremity during the single support phase in the kendo motion. Our result also showed that as for the peak foot pronation angle and the pronation ROM there was no significant difference between different distances to the target. Conclusion. We provided the basic biomechanical information during the kendo strike-thrust motion, and the result will help us to understand the Achilles tendon injury occurrence in kendo athletes.
Nishikawa T.,Ryotokuji University |
Tanaka K.,Juntendo University |
Tanaka K.,High Energy Accelerator Research Organization
Nuclear Physics B | Year: 2014
We discuss the QCD sum rule calculation of the heavy-quark effective theory parameters, λE and λH, which correspond to matrix elements representing quark-gluon three-body components in the B-meson wavefunction. We derive the sum rules for λE,H calculating the new higher-order QCD corrections, i.e., the order αs radiative corrections to the Wilson coefficients associated with the dimension-5 quark-gluon mixed condensates, and the power corrections due to the dimension-6 vacuum condensates. We find that the new radiative corrections significantly improve the stability of the corresponding Borel sum rules and lead to the reduction of the values of λE,H. We also discuss the renormalization-group improvement for the sum rules and present update on the values of λE,H. © 2013 The Authors.