Temporal dynamics of the sensorimotor convergence underlying voluntary limb movement

運動指令信号と感覚信号が統合されて運動が作り出される過程を発見 --中枢神経系と末梢神経系の大規模神経活動記録から明らかに--. 京都大学プレスリリース. 2022-11-24.Descending motor drive and somatosensory feedback play important roles in modulating muscle activity. Numerous studies have characterized the organization of neuronal connectivity in which descending motor pathways and somatosensory afferents converge on spinal motor neurons as a final common pathway. However, how inputs from these two pathways are integrated into spinal motor neurons to generate muscle activity during actual motor behavior is unknown. Here, we simultaneously recorded activity in the motor cortices (MCx), somatosensory afferent neurons, and forelimb muscles in monkeys performing reaching and grasping movements. We constructed a linear model to explain the instantaneous muscle activity using the activity of MCx (descending input) and peripheral afferents (afferent input). Decomposition of the reconstructed muscle activity into each subcomponent indicated that muscle activity before movement onset could first be explained by descending input from mainly the primary motor cortex and muscle activity after movement onset by both descending and afferent inputs. Descending input had a facilitative effect on all muscles, whereas afferent input had a facilitative or suppressive effect on each muscle. Such antagonistic effects of afferent input can be explained by reciprocal effects of the spinal reflex. These results suggest that descending input contributes to the initiation of limb movement, and this initial movement subsequently affects muscle activity via the spinal reflex in conjunction with the continuous descending input. Thus, spinal motor neurons are subjected to temporally organized modulation by direct activation through the descending pathway and the lagged action of the spinal reflex during voluntary limb movement

Parameter identification of nonlinear viscoelastic model with impact area parameter for sport surface by using multi-intensity multi-area impact test

AbstractIn previous studies, we proposed various models of material and methods for identifying the parameters of these models by multi-intensity impact test. Especially, the exponential funtion type nonlinear Voigt model shows an excellent accuracy for identifying the property of material behavior. Although other papers show that this model is applicable to the case of varying impact duration and various temperatures, we have not yet discussed how the properties would change as the impact area changed. The purpose of this study is to propose an identification technique of nonlinear Voigt model with hysteresis and dependence on impact area by multi-intensity multi-area impact test. The nonlinear elastic element of this model is expressed by the exponential function based on displacement and impact area. And the nonlinear viscous element of the model is expressed by the product of the exponential function based on displacement and the exponential function based on velocity

TRPC6 counteracts TRPC3-Nox2 protein complex leading to attenuation of hyperglycemia-induced heart failure in mice

Excess production of reactive oxygen species (ROS) caused by hyperglycemia is a major risk factor for heart failure. We previously reported that transient receptor potential canonical 3 (TRPC3) channel mediates pressure overload-induced maladaptive cardiac fibrosis by forming stably functional complex with NADPH oxidase 2 (Nox2). Although TRPC3 has been long suggested to form hetero-multimer channels with TRPC6 and function as diacylglycerol-activated cation channels coordinately, the role of TRPC6 in heart is still obscure. We here demonstrated that deletion of TRPC6 had no impact on pressure overload-induced heart failure despite inhibiting interstitial fibrosis in mice. TRPC6-deficient mouse hearts 1 week after transverse aortic constriction showed comparable increases in fibrotic gene expressions and ROS production but promoted inductions of inflammatory cytokines, compared to wild type hearts. Treatment of TRPC6-deficient mice with streptozotocin caused severe reduction of cardiac contractility with enhancing urinary and cardiac lipid peroxide levels, compared to wild type and TRPC3-deficient mice. Knockdown of TRPC6, but not TRPC3, enhanced basal expression levels of cytokines in rat cardiomyocytes. TRPC6 could interact with Nox2, but the abundance of TRPC6 was inversely correlated with that of Nox2. These results strongly suggest that Nox2 destabilization through disrupting TRPC3-Nox2 complex underlies attenuation of hyperglycemia-induced heart failure by TRPC6.Fil: Oda, Sayaka. Okazaki Institute for Integrative Bioscience; Japón. SOKENDAI; JapónFil: Numaga Tomita, Takuro. Okazaki Institute for Integrative Bioscience; Japón. SOKENDAI; JapónFil: Kitajima, Naoyuki. Okazaki Institute for Integrative Bioscience; Japón. Kyushu University; JapónFil: Tomizaki, Takashi. Okazaki Institute for Integrative Bioscience; Japón. Kyushu University; Japón. University of Tsukuba; JapónFil: Harada, Eri. Ajinomoto Co.; Japón. EA Pharma Co.; JapónFil: Shimauchi, Tsukasa. Okazaki Institute for Integrative Bioscience; Japón. Kyushu University; JapónFil: Nishimura, Akiyuki. Okazaki Institute for Integrative Bioscience; Japón. SOKENDAI; Japón. Ajinomoto Co.; JapónFil: Ishikawa, Tatsuya. Kyushu University; Japón. Ajinomoto Co.; Japón. EA Pharma Co.; JapónFil: Kumagai, Yoshito. University of Tsukuba; JapónFil: Birnbaumer, Lutz. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Nishida, Motohiro. Okazaki Institute for Integrative Bioscience; Japón. SOKENDAI; Japón. Kyushu University; Japón. PRESTO; Japó

ステロイド投与家兎における静脈病変 : ステロイド性大腿骨頭壊死症の病因病態に注目して

取得学位 : 博士（医学）, 学位授与番号 : 医博甲第1179号, 学位授与年月日：平成7年5月31日,学位授与年：199

The effects of herring-roe lyophilized powder on lipid metabolism

AbstractHerring-roe, which contains large amounts of docosahexaenoic acid and eicosapentaenoic acid, has anti-dyslipidemia effects. Here, we evaluated the effects of herring-roe on lipid metabolism in 33 adult subjects in a randomized, double-blind, placebo-controlled study. We divided the subjects into a test group that ingested herring-roe lyophilized powder (herring-roe powder) and a placebo group that ingested non-herring-roe powder, with each member of each group ingesting 15 g daily for 8 weeks. Hematological tests and body composition measurements were performed before and after 4, 6, and 8 weeks of the study period. Although no significant differences in low density lipoprotein were observed, high density lipoprotein was found to be increased in subjects who ingested herring-roe powder. In addition, the level of free fatty acid was significantly improved in the herring-roe powder group. These results suggest that ingestion of herring-roe could influence lipid metabolism

Saikokeishito Extract Exerts a Therapeutic Effect on α-Naphthylisothiocyanate-Induced Liver Injury in Rats through Attenuation of Enhanced Neutrophil Infiltration and Oxidative Stress in the Liver Tissue

We examined whether Saikokeishito extract (TJ-10), a traditional Japanese herbal medicine, exerts a therapeutic effect on α-naphthylisothiocyanate (ANIT)-induced liver injury in rats through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue. In rats treated once with ANIT (75 mg/kg, i.p.), liver injury with cholestasis occurred 24 h after treatment and progressed at 48 h. When ANIT-treated rats orally received TJ-10 (0.26, 1.3 or 2.6 g/kg) at 24 h after the treatment, progressive liver injury with cholestasis was significantly attenuated at 48 h after the treatment at the dose of 1.3 or 2.6 g/kg. At 24 h after ANIT treatment, increases in hepatic lipid peroxide and reduced glutathione contents and myeloperoxidase activity occurred with decreases in hepatic superoxide dismutase and glutathione reductase activities. At 48 h after ANIT treatment, these changes except for reduced glutathione were enhanced with decreases in catalase, Se-glutathione peroxidase, and glucose-6-phosphate dehydrogenase activities. TJ-10 (1.3 or 2.6 g/kg) post-administered to ANIT-treated rats attenuated these changes found at 48 h after the treatment significantly. These results indicate that TJ-10 exerts a therapeutic effect on ANIT-induced liver injury in rats possibly through attenuation of enhanced neutrophil infiltration and oxidative stress in the liver tissue

The Relationship between Inferior Vena Cava Distensibility and Arterial Blood Pressure

The purpose of this study was to clarify the relationship between the inferior vena cava distensibility and blood pressure. Six Japanese healthy males volunteered to participate in this study. We measured the cross-sectional area of inferior vena cava (CSAivc) and blood pressure at rest and during passive leg raising in supine position. We calculated the change rates of each parameter, based on the value at rest in supine position. We observed a negative correlation between the change rate of CSAivc and systolic blood pressure (P<0.05). These results suggest that the inferior vena cava distensibility affects partially systolic blood pressure

Effects of Eating or Skipping Breakfast on Heart Rate and Oxygen Uptake

The purpose of this study was to compare changes in heart rate, oxygen uptake, blood pressure and oral temperature between subjects eating breakfast and subjects skipping breakfast when they exercise each day at 11:00 AM and 2:00 PM. The study design included two different groups, a breakfast group and a skipping group. Subjects rested for five minutes, and they exercised on a pendulum ergometer for twenty minutes. After exercising, the resistance was returned to zero for a one minute cool down followed by five more minutes of complete rest(recovery phase). Oral temperatures of the skipping group were lower than those of the breakfast group at 11:00 AM. Diet induced thermogenesis (DIT), which increases core body temperature, is generated by eating breakfast. In the skipping group, the resting heart rates at 11:00 AM were lower than at 2:00 PM. A significant difference in heart rate after the first minute of exercise was seen between 11:00 AM and 2:00 PM in the skipping group. These results suggested that when skipping breakfast, the heart rate response immediately after beginning exercise is slow in the morning. Although all subjects did cooling down for one minute after exercising, oxygen uptake during the recovery phase in the skipping group at 11:00 AM was significantly higher than at rest. These results suggest that eating breakfast has a physiological influence on both heart rate and oxygen uptake

An attempt to construct the obsessive-compulsive tendencies scale

Obsessive-compulsive (OC) symptoms have been increasing among nonclinical populations. We constructed the scale of OC tendencies to measure the OC symptoms observed in nonclinicals. The Maudsley Obsessional-Compulsive Inventory (MOCI), the Padua Inventory (PI) and the Indecisiveness scale were administered to Japanese nonclinical students. Factor analysis followed by promax rotation extracted four factors; intrusion, checking, indecisiveness and cleaning, respectively. Inter-factor correlations showed that checking factor correlated with cognitive factors (intrusion and indecisiveness) stronger than cleaning factor did. The 24-items short version of the OC tendencies scale had good reliability (Cronbach's α : .72-.86; test-retest : r=.74-.82) and good criterion-related validity (with MMPI OC state : r=.21-.52). The OC tendencies scale was administered to OC disorder patients. OC disorder patients' scores of this scale was higher than those of nonclinicals. These results indicated the OC tendencies scale had the clinical validity