The Impact of Potassium Dynamics on Cardiomyocyte Beating in Hemodialysis Treatment.

Background: Observational studies of intermittent hemodialysis therapy have reported that the excess decrease in K+ concentration in plasma (KP) during treatment is associated with the destabilization of cardiac function. Elucidating the mechanism by which the decrease in KP impairs myocardial excitation is indispensable for a deeper understanding of prescription design. Methods: In this study, by using an electrophysiological mathematical model, we investigated the relationship between KP dynamics and cardiomyocyte excitability for the first time. Results: The excess decrease in KP during treatment destabilized cardiomyocyte excitability through the following events: (1) a decrease in KP led to the prolongation of the depolarization phase of ventricular cells due to the reduced potassium efflux rate of the Kr channel, temporarily enhancing contraction force; (2) an excess decrease in KP activated the transport of K+ and Na+ through the funny channel in sinoatrial nodal cells, disrupting automaticity; (3) the excess decrease in KP also resulted in a significant decrease in the resting membrane potential of ventricular cells, causing contractile dysfunction. Avoiding an excess decrease in KP during treatment contributed to the maintenance of cardiomyocyte excitability. Conclusions: The results of these mathematical analyses showed that it is necessary to implement personal prescription or optimal control of K+ concentration in dialysis fluid based on predialysis KP from the perspective of regulatory science in dialysis treatment.

Characteristics of EEG power spectra involved in the proficiency of motor learning.

Neuromodulation techniques for modulating brain activity can affect performance in a variety of behaviors. Techniques including transcranial alternating current stimulation and random noise stimulation can modulate neural oscillations. However, the intervention effect of neuromodulation approaches on motor learning is poor, partly because the electroencephalography (EEG) power spectra associated with the motor learning process has not yet been fully elucidated. Therefore, we investigated the characteristics of EEG power spectra in the process of motor learning in 15 right-handed healthy participants (5 females; mean age = 22.8 ± 3.0 years). The motor task was a ball-rotation task in which participants rotated two balls in the palm of their left hand. Participants performed a pre-test, the motor learning tasks, and a post-test. In the motor learning tasks, twenty 60 s trials were performed in the clockwise (CW) direction. Before and after the motor learning tasks, CW and counterclockwise (CCW; control condition) tasks were performed for 60 s each as pre- and post-tests. Therefore, CW direction was set as a motor learning task, while CCW was a test-only control task. EEG was recorded during the tests and tasks, and the power spectra in the alpha, beta, and gamma oscillations were calculated and compared between pre- and post-tests. The results showed that in the CW post-test, the power of the gamma band in the left parietal areas and the right frontal area was significantly higher than in the pre-test. In the CCW, there was no significant difference in each band at each area between the pre- and post-tests. Our findings reveal the characteristics of the EEG spectra related to the motor learning process. These results may help to establish more effective neuromodulation approaches to modifying neural oscillations in motor learning, including in rehabilitation fields.

Outcomes of adult patients with early T-cell precursor (ETP) acute lymphoblastic leukemia/lymphoma (ALL) and non-ETP T-ALL.

Early T-cell precursor (ETP) acute lymphoblastic leukemia/lymphoma (ALL) is generally considered to be a high-risk subtype. We retrospectively analyzed the clinical outcomes of adult patients diagnosed with ETP-ALL or other T-cell ALL (non-ETP T-ALL). The subjects were 82 patients (ETP-ALL: n = 18, non-ETP T-ALL: n = 64) for whom relevant immunophenotype data needed for classification were available. ETP-ALL patients were older (median age, 50.5 vs. 33.5 years, P = 0.042) and had less mediastinal involvement (27.8 vs. 73.4%, P < 0.001). The rate of complete remission (CR) with the first induction therapy was significantly lower in the ETP group (33.3 vs. 64.0%, P = 0.03), but the CR rate within 2 cycles of chemotherapy did not differ significantly (61.1 vs. 76.6%, P = 0.232). The 3-year overall survival (OS) rate was also similar in both groups (43.2 vs. 45.8%, P = 0.992). The ETP phenotype had no impact on survival in the transplant group or the non-transplant group. A multivariate analysis identified the male sex as a poor prognostic factor (HR: 4.43, P < 0.01), but not the immunophenotype of ETP. The prognosis for adult patients with ETP-ALL was comparable to that of non-ETP T-ALL patients. However, further studies aimed at improving the remission rate for ETP-ALL are needed.

Clarify Sit-to-Stand Muscle Synergy and Tension Changes in Subacute Stroke Rehabilitation by Musculoskeletal Modeling.

Post-stroke patients exhibit distinct muscle activation electromyography (EMG) features in sit-to-stand (STS) due to motor deficiency. Muscle activation amplitude, related to muscle tension and muscle synergy activation levels, is one of the defining EMG features that reflects post-stroke motor functioning and motor impairment. Although some qualitative findings are available, it is not clear if and how muscle activation amplitude-related biomechanical attributes may quantitatively reflect during subacute stroke rehabilitation. To better enable a longitudinal investigation into a patient's muscle activation changes during rehabilitation or an inter-subject comparison, EMG normalization is usually applied. However, current normalization methods using maximum voluntary contraction (MVC) or within-task peak/mean EMG may not be feasible when MVC cannot be obtained from stroke survivors due to motor paralysis and the subject of comparison is EMG amplitude. Here, focusing on the paretic side, we first propose a novel, joint torque-based normalization method that incorporates musculoskeletal modeling, forward dynamics simulation, and mathematical optimization. Next, upon method validation, we apply it to quantify changes in muscle tension and muscle synergy activation levels in STS motor control units for patients in subacute stroke rehabilitation. The novel method was validated against MVC-normalized EMG data from eight healthy participants, and it retained muscle activation amplitude differences for inter- and intra-subject comparisons. The proposed joint torque-based method was also compared with the common static optimization based on squared muscle activation and showed higher simulation accuracy overall. Serial STS measurements were conducted with four post-stroke patients during their subacute rehabilitation stay (137 ± 22 days) in the hospital. Quantitative results of patients suggest that maximum muscle tension and activation level of muscle synergy temporal patterns may reflect the effectiveness of subacute stroke rehabilitation. A quality comparison between muscle synergies computed with the conventional within-task peak/mean EMG normalization and our proposed method showed that the conventional was prone to activation amplitude overestimation and underestimation. The contributed method and findings help recapitulate and understand the post-stroke motor recovery process, which may facilitate developing more effective rehabilitation strategies for future stroke survivors.

[Development of severe aplastic anemia during steroid therapy for autoimmune hemolytic anemia].

A 50-year-old male patient was admitted for close monitoring of anemia (hemoglobin level, 5.0 g/dl). Autoimmune hemolytic anemia (AIHA) of warm type was diagnosed based on the elevated reticulocyte and bone marrow erythroblast counts, elevated indirect bilirubin level, serum haptoglobin level below the detection limit, and positive direct Coombs test result. The patient responded to prednisolone 60 mg/day (1.0 mg/kg); however, pancytopenia was observed during gradual dose tapering and maintenance therapy. The bone marrow showed remarkable hypoplastic findings, and magnetic resonance imaging scans of the thoracolumbar spinal cord showed an overgrowth of the adipose tissue. Thus, the patient was diagnosed with aplastic anemia (AA) stage 4. He was successfully treated with a combination of immunosuppressive therapy (anti-thymocyte globulin +cyclosporine), which allowed him to reduce his dependence on transfusions. However, the direct Coombs test result remained positive even after hematopoietic recovery. Aplastic anemia following AIHA treatment is extremely rare and has not been reported previously.

WinBEST-KIT: Biochemical Reaction Simulator for Analyzing Multi-Layered Metabolic Pathways.

We previously developed the biochemical reaction simulator WinBEST-KIT. In recent years, research interest has shifted from analysis of individual biochemical reactions to analysis of metabolic pathways as systems. These large-scale and complicated metabolic pathways can be considered as characteristic multi-layered structures, which, for convenience, are separated from whole biological systems according to their specific roles. These pathways include reactants having the same name but with unique stoichiometric coefficients arranged across many different places and connected between arbitrary layers. Accordingly, in this study, we have developed a new version of WinBEST-KIT that allows users (1) to utilize shortcut symbols that can be arranged with multiple reactants having the same name but with unique stoichiometric coefficients, thereby providing a layout that is similar to metabolic pathways depicted in biochemical textbooks; (2) to create layers that divide large-scale and complicated metabolic pathways according to their specific roles; (3) to connect the layers by using shortcut symbols; and (4) to analyze the interactions between these layers. These new and existing features allow users to create and analyze such multi-layered metabolic pathways efficiently. Furthermore, WinBEST-KIT supports SBML, making it possible for users to utilize these new and existing features to create and publish SBML models.

Electrophysiological insights into the relationship between calcium dynamics and cardiomyocyte beating function in chronic hemodialysis treatment.

For patients in which the Ca2+ concentration of dialysis fluid is lower than that in plasma, chronic hemodialysis treatment often leads to cardiac beating dysfunction. By applying these conditions to an electrophysiological mathematical model, we evaluated the impact of body fluid Ca2+ dynamics during treatment on cardiomyocyte beating and, moreover, explored measures that may prevent cardiomyocyte beating dysfunction. First, Ca2+ concentrations in both plasma and interstitial fluid were decreased with treatment time, which induced both a slight decline in beating rhythm on a sinoatrial nodal cell and a wane in contraction force on a ventricular cell. These simulated results were in agreement with clinical observations. Next, a relationship between the intracellular Ca2+ concentration and ion current dynamics of ion transporters were examined to elucidate the mechanism underlying cardiomyocyte beating dysfunction. The inward current of the Na/Ca exchanger (NCX) increased with a decrease in Ca2+ concentration in interstitial fluid and induced a reduction in intracellular Ca2+ concentration during treatment. Furthermore, the decline in intracellular Ca2+ concentration reduced the contraction force. These findings implied that ion transport through the NCX is a dominant factor that induces cardiomyocyte beating dysfunction during hemodialysis. Finally, the replenishment of Ca2+ or application of an NCX inhibitor during treatment suppressed the decrease in intracellular Ca2+ concentration and contributed to the stabilization of cardiomyocyte beating function. In summary, the clinical implementation of hepatically cleared NCX inhibitor may be a suitable approach to improving the quality of life for patients on chronic hemodialysis.

[Clinicopathological features of hemorrhagic gastrointestinal stromal tumor].

In order to demonstrate the bleeding risk factors of GIST (gastrointestinal stromal tumor), we retrospectively investigated clinicopathological features between hemorrhagic (H group, 24 cases) and nonhemorrhagic GIST (NH group, 30 cases). In addition, we investigated features between the E group (6 cases) necessitating TAE (trans-catheter arterial embolization) and NE group (other 48 cases). Whereas H group partly includes high-risk grade GIST with chronic bleeding, meanwhile the E group (reflecting acute bleeding) is characterized by a highly enhanced mass with ulceration, comprising of smaller low-risk grade GIST. Amongst the 29 cases for forceps biopsy, which were 6 cases (21%) including one of E group, needed be hospitalized for postbiopsy bleeding. Acute bleeding in GIST may not be associated with malignant transformation. Postbiopsy bleeding or massive hemorrhage can also be encountered particularly in highly enhanced GIST with ulceration, even with a small and low-risk grade.

Mathematical analysis-based feasibility study of pre-emptive medicine for Staphylococcus aureus infectious disease: Early detection and antibiotic-free maintenance therapy.

Global efforts are being made to achieve the clinical implementation of pre-emptive medicine for Staphylococcus aureus (S. aureus) infectious disease, which will realize both early detection at the pre-symptom stage and bacteriostatic therapy by antibiotic-free medicine in a future. Several research groups proposed the intercellular signal transduction factor (auto-inducing peptide: AIP) antibody, the synthesised AIP analogues and a cyclic depsipeptide with high constitutional similarity to AIP as a candidate of the pre-emptive medicine for S. aureus infectious disease. In this paper, to evaluate a validity of them, we mathematically explored both a pre-symptom associated with the pathogenic expression process of S. aureus and several therapeutic targets that delay or suppress the appearance of the pre-symptom. The stochastic mathematical analysis identified a peak of fluctuation in intracellular AgrD concentration as the pre-symptom. Moreover, employing parameter sensitivity analysis, the enhancement of binding inhibition between AgrC receptor and AIP was identified as effective therapeutic target. Based on these findings, we evaluated a feasibility of above-mentioned candidates, and concluded that the continuous application of AgrC receptor antagonists, such as the synthesised AIP analogues and a cyclic depsipeptide with high constitutional similarity to AIP, is useful as pre-emptive medicine for S. aureus infectious disease.

Curcumin inhibits epithelial-mesenchymal transition in oral cancer cells via c-Met blockade.

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer. OSCC cells are highly invasive, a characteristic that involves epithelial-mesenchymal transition (EMT); the conversion of immotile epithelial cells into motile mesenchymal cells. EMT is involved in the progression of various types of cancer by promoting tumour cell scattering and conferring to these cells cancer stem cell (CSC)-like characteristics, such as self-renewal. Hepatocyte growth factor (HGF) signalling plays an important role in EMT induction and, therefore, contributes to cell invasion and metastasis in cancer. Due to its potential chemopreventative and anti-tumour activities, curcumin has attracted much interest and has been shown to act as a potent EMT inhibitor in various types of cancer. However, at present, the potential effects of curcumin on HGF-induced EMT in OSCC have not been investigated. Here, we demonstrated that HGF signalling could induce EMT in the HSC4 and Ca9-22 OSCC cell lines via the HGF receptor c-Met and downstream activation of the pro-survival ERK pathway. Notably, curcumin inhibited HGF-induced EMT and cell motility in HSC-4 and Ca9-22 cells via c-Met blockade. Therefore, these findings establish curcumin as a candidate drug for OSCC treatment. Furthermore, curcumin was able to effectively inhibit the HGF-induced increase in the levels of vimentin by downregulating the expression of phosphorylated c-Met, an ERK. In conclusion, the results of the present study demonstrated that curcumin was able to reverse HGF-induced EMT, possibly by inhibiting c-Met expression in oral cancer cells, providing a strong basis for the development of novel approaches for the treatment of oral cancer.

[Acquired hemophilia A accompanied by immune thrombocytopenia].

A 72-year-old man was hospitalized because of thrombocytopenia (0.5×104/µl) and anemia. The bone marrow test result revealed excessive numbers of megakaryocytes and no platelet adhesion. Furthermore, platelet-associated immunoglobulin G levels were high, and he was tested positive for Helicobacter pylori antibody. On the basis of these findings, immune thrombocytopenia was diagnosed. The patient was initially treated with eradication therapy; prednisolone, 20 mg/day (0.5 mg/kg) and a thrombopoietin receptor agonist 12.5 mg/day. During the course of treatment, the anemia worsened. Detailed examination revealed marked prolongation of activated partial thromboplastin time and inhibition of factor VIII activity. Therefore, he was diagnosed with acquired hemophilia A. Although extensive muscle hemorrhage had occurred, hemostatic therapy comprising intensification of the immunosuppressive therapy and administration of recombinant activated factor VII resulted in successful hemostasis. As the treatment progressed, inhibition of factor VIII recurred temporarily; however, immunosuppressive therapy was continued. No recurrence was observed even after 1 year of the onset of both diseases.

Synthetic microbial consortium with specific roles designated by genetic circuits for cooperative chemical production.

Synthetic microbial consortia consisting of microorganisms with different synthetic genetic circuits or divided synthetic metabolic pathway components can exert functions that are beyond the capacities of single microorganisms. However, few consortia of microorganisms with different synthetic genetic circuits have been developed. We designed and constructed a synthetic microbial consortium composed of an enzyme-producing strain and a target chemical-producing strain using Escherichia coli for chemical production with efficient saccharification. The enzyme-producing strain harbored a synthetic genetic circuit to produce beta-glucosidase, which converts cellobiose to glucose, destroys itself via the lytic genes, and release the enzyme when the desired cell density is reached. The target chemical-producing strain was programmed by a synthetic genetic circuit to express enzymes in the synthetic metabolic pathway for isopropanol production when the enzyme-producing strain grows until release of the enzyme. Our results demonstrate the benefits of synthetic microbial consortia with distributed tasks for effective chemical production from biomass.

WinBEST-KIT: Biochemical reaction simulator that can define and customize algebraic equations and events as GUI components.

We previously developed Windows-based Biochemical Engineering System analyzing Tool-KIT (WinBEST-KIT), a biochemical reaction simulator for analyzing large-scale and complicated biochemical reaction networks. One particularly notable feature is the ability for users to define original mathematical equations for representing unknown kinetic mechanisms and customize them as GUI components for representing reaction steps. Many simulators support System Biology Markup Language SBML; however, since the definition of the algebraic equations (AssignmentRule) and the events are made through an interface that is distinct from the definition of the reaction steps, there are tough works to define them. Accordingly, we have developed a new version of WinBEST-KIT that allows users to define the algebraic equations and the events through the same interface as those used in the definition of the reaction steps and customize them as GUI components appearing in the symbol selection area. The customized algebraic equations and events can thus be visually arranged at any time and any place. It also allows users to easily understand the roles of the algebraic equations and the events. We have also implemented other useful features, including importing/exporting of SBML format files, exporting to MATLAB, and merging the existing models into the model currently being created. The current version of WinBEST-KIT is freely available at http://winbest-kit.org/.

Gas gangrene in the deep spaces of the head and neck visualized on computed tomography images.

Cellulitis accompanied by gas gangrene is a rapidly-spreading and potentially fatal infection. Here, we present a case of gas gangrene in the deep spaces of the head and neck in an elderly woman, diagnosed by computed tomography (CT). An 86-year-old woman with Alzheimer's disease, hypertension, hyperlipidemia, and osteoporosis was referred to our institute by her local dentist. The patient exhibited trismus caused by severe swelling in the left submandibular area. CT images of the head and neck area showed swelling of the cervical tissue with air in the parapharyngeal and masticator spaces. She was treated with antibiotics, followed by drainage. Although the therapy was continued, the patient died from a cardiac complication on hospital day 42. Our case highlights the usefulness of CT for diagnosing gas gangrene in the deep spaces of the head and neck in a woman with Alzheimer's disease.

Evaluation of the mass transfer rate using computer simulation in a three-dimensional interwoven hollow fiber-type bioartificial liver.

OBJECTIVES: To determine the most efficient design of a hollow fiber-based bioreactor device for a bioartificial liver support system through comparative bioengineering evaluations. RESULTS: We compared two types of hollow fiber-based bioreactors, the interwoven-type bioreactor (IWBAL) and the dialyzer-type bioreactor (DBAL), by evaluating the overall mass transfer coefficient (K) and the convective coefficient (X). The creatinine and albumin mass transfer coefficients and convective coefficients were calculated using our mathematical model based on the homoporous theory and the modified Powell method. Additionally, using our model, we simulated the mass transport efficiency in clinical-scale BALs. The results of this experiment demonstrate that the mass transfer coefficients for creatinine and albumin increased proportionally with velocity with the IWBAL, and were consistently greater than that found with the DBAL. These differences were further enhanced in the simulation of the large-scale model. CONCLUSIONS: Our findings indicate that the IWBAL with its unique 30° cross hollow fiber design can provide greater solute removal and more efficient metabolism when compared to the conventional DBAL design.

Differential effects of high-definition transcranial direct current stimulation on verbal working memory performance according to sensory modality.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that modulates cortical excitability in a polarity-dependent manner. The diffuse nature of tDCS makes it difficult to investigate the optimal stimulation parameters for more effective and specific cognitive enhancement; to address this deficit, a more focalized stimulation technique, high-definition tDCS (HD-tDCS), has been developed. To date, only a few studies have examined the effects of HD-tDCS on cognitive functions; and none has investigated the effects of HD-tDCS on different sensory modalities of verbal working memory. Therefore, the present study compared the effects of prefrontal HD-tDCS on visual and auditory working memory tasks. Twenty healthy participants completed three sessions of each modality task, and additionally a sustained attention task. Anodal or sham HD-tDCS was administered to the dorsolateral prefrontal cortex (DLPFC) during the second session of the task in a parallel, single-blind design. Anodal stimulation to the DLPFC significantly enhanced the visual verbal working memory accuracy during and 20 min after the stimulation. In contrast, auditory verbal working memory performance was not modulated by anodal stimulation. Anodal stimulation to the DLPFC showed no effect on any other cognitive functions. The present study revealed the differential effects of HD-tDCS on two different modalities (visual vs. auditory) of working memory performance: important preliminary findings for the establishment of a more effective and specific use of tDCS.

Facile Preparation and Characterization of Short-Fiber and Talc Reinforced Poly(Lactic Acid) Hybrid Composite with In Situ Reactive Compatibilizers.

Hybrid composites of fillers and/or fibers reinforced polymer was generally produced by masterbatch dilution technique. In this work, the simplified preparation was introduced for the large volume production of 30 wt % short-fiber and talcum reinforced polymer hybrid composite by direct feeding into twin-screw extruder. Multifunctional epoxide-based terpolymer and/or maleic anhydride were selected as in situ reactive compatibilizers. The influence of fiber and talcum ratios and in situ reactive compatibilizers on mechanical, dynamic mechanical, morphological and thermal properties of hybrid composites were investigated. The morphological results showed the strong interfacial adhesion between fiber or talcum and Poly(lactic acid) (PLA) matrix due to a better compatibility by reaction of in situ compatibilizer. The reactive PLA hybrid composite showed the higher tensile strength and the elongation at break than non-compatibilized hybrid composite without sacrificing the tensile modulus. Upon increasing the talcum contents, the modulus and storage modulus of hybrid composites were also increased while the tensile strength and elongation at break were slightly decreased compared to PLA/fiber composite. Talcum was able to induce the crystallization of PLA hybrid composites.

A fertility-restoring genotype of beet (Beta vulgaris L.) is composed of a weak restorer-of-fertility gene and a modifier gene tightly linked to the Rf1 locus.

Cytoplasmic male sterility (CMS) is a plant trait that involves interactions between nuclear- and mitochondrial genomes. In CMS, the nuclear restorer-of-fertility gene (Rf), a suppressor of male-sterility inducing mitochondria, is one of the best known genetic factors. Other unidentified genetic factors may exist but have not been well characterized. In sugar beet (Beta vulgaris L.), CMS is used for hybrid seed production, but few male-sterility inducing nuclear genotypes exist. Such genotypes could be introduced from a closely related plant such as leaf beet, but first the fertility restoring genotype of the related plant must be characterized. Here, we report the discovery of a Japanese leaf beet accession 'Fukkoku-ouba' that has both male-sterility inducing and fertility restoring genotypes. We crossed the leaf beet accession with a sugar beet CMS line, developed succeeding generations, and examined the segregation of two DNA markers that are linked to two sugar beet Rfs, Rf1 and Rf2. Only the Rf2 marker co-segregated with fertility restoration in every generation, implying that the Rf1 locus in leaf beet is occupied by a non-restoring allele. Fertility restoration was incomplete without a genetic factor closely linked to Rf1, leading to the assumption that the Rf1 locus encodes a modifier that cannot restore fertility by itself but perhaps strengthens another Rf. We sequenced the apparently non-restoring 'Fukkoku-ouba' rf1 gene-coding region and found that it closely resembles a restoring allele. The protein product demonstrated its potential to suppress CMS in transgenic suspension cells. In contrast, 'Fukkoku-ouba' rf1 transcript abundance was highly reduced compared to that of the restoring Rf1. Consistently, changes in protein complexes containing CMS-associated mitochondrial protein in anthers were very minor. Accordingly, we concluded that 'Fukkoku-ouba' rf1 is a hypomorph that acts as a non-restoring allele but has the potential to support another Rf, i.e. it is a modifier candidate.

Gender-specific associations of depression and anxiety symptoms with mental rotation.

BACKGROUND: Men score higher on mental rotation tasks compared to women and suffer from depression and anxiety at half the rate of women. The objective of this study was to confirm the gender-specific effects of depression and anxiety on mental rotation performance. METHODS: We collected data in non-experimental conditions from 325 university students at three universities. Participants completed rating scales of depressive and anxiety symptoms, and then simultaneously performed a mental rotation task using tablet devices. RESULTS: We observed no significant difference between men and women in the depressive and anxiety symptoms and task response time. Men had a significantly higher correct answer rate compared with women. The scores of depression and anxiety of all participants were positively correlated. Task response time correlated positively with intensity of depressive symptoms and anxiety in women, but not in men. Women with high depressive symptoms had significantly longer response times than did women with low depressive symptoms, while men had no differences due to depressive symptoms. LIMITATIONS: We did not directly examine brain functions; therefore, the underlying neurobiological results are only based on previous knowledge and action data. CONCLUSIONS: The pathology of depression and anxiety was reflected in the correct answer rate and response time in relation to the gender difference of brain function used in mental rotation.

Comparison of brain activity between motor imagery and mental rotation of the hand tasks: a functional magnetic resonance imaging study.

Motor imagery (MI) has been considered effective in learning and practicing movements in many fields. However, when evaluating the effectiveness of this technique, the examiner has no way of assessing the participant's motor imagery process. As an alternative, we have been exploring a mental body-part rotation task, in which the examiner can estimate the participant's motivation and ability to sustain attention through the scored results. In this study, we aimed to investigate the possible application of a mental rotation (MRot) task and used fMRI to compare the brain activity during the MRot task with that during an MI task in healthy volunteers. Increased blood oxygenation level-dependent signals were observed bilaterally in the premotor areas and supplementary motor area during performance of both MI and MRot tasks. Our findings suggest that MRot could be an alternative to MI.