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This study aims to investigate the structural reorganization in the sensorimotor area of the brain in patients with gliomas, distinguishing between those with impaired and unimpaired strength. Using voxel‐based morphometry (VBM) and region of interest (ROI) analysis, gray matter volumes (GMV) were compared in the contralesional primary motor gyrus, primary sensory gyrus, premotor area, bilateral supplementary motor area, and medial Brodmann area 8 (BA8). The results revealed that in patients with right hemisphere gliomas, the right medial BA8 volume was significantly larger in the impaired group than in the unimpaired group, with both groups exceeding the volume in 16 healthy controls (HCs). In patients with left hemisphere gliomas, the right supplementary motor area (SMA) was more pronounced in the impaired group compared to the unimpaired group, and both groups were greater than HCs. Additionally, the volumes of the right medial BA8 in both the impaired group were greater than HCs. Contralateral expansions in the gray matter of hand‐ and trunk‐related cortices of the premotor area, precentral gyrus, and postcentral gyrus were observed compared to HCs. Furthermore, a negative correlation was found between hand Medical Research Council (MRC) score and volumes of the contralateral SMA and bilateral medial BA8. Notably, our findings reveal consistent results across both analytical approaches in identifying significant structural reorganizations within the sensorimotor cortex. These consistent findings underscore the adaptive neuroplastic responses to glioma presence, highlighting potential areas of interest for further neurosurgical planning and rehabilitation strategies. [ABSTRACT FROM AUTHOR]

several studies state that the comprehension of the meaning of language is based on concrete and modal simulations. This assertion is evidenced by the activation of sensorimotor brain areas during the processing of movement-related linguistic stimuli. This paper aims to review the literature on embodied simulation as a mechanism for comprehending concrete and abstract language. A literature search was conducted in major international databases for articles related to embodied simulation from the fields of neuroscience and psycholinguistics. In this regard, the article presents a section on embodied simulation as a condition for language comprehension, as well as empirical evidence from neuroscience regarding the activations of sensory and motor areas during the simulation for such comprehension. Subsequently, studies are presented in the psycholinguistic framework that account for these simulation processes in the comprehension of abstract language, more specifically, metaphorical language, taking into account the Conceptual Metaphor Theory. Finally, the evidence presented in the literature reviewed leads one to conclude that simulation is one of the key elements for comprehending concrete and abstract language, as in the case of metaphor. However, for such comprehension, other elements are required such as association, mental images, and imagination that allow for the recreation of abstract concepts that do not directly relate to embodied experiences. [ABSTRACT FROM AUTHOR]

Robot-assisted body movements are a useful approach for the rehabilitation of motor dysfunction. Various robots based on end-effector or exoskeleton type have been proposed. However, the effect of these robots on brain activity during assistive lower limb movements remains unclear. In this study, we evaluated brain activity results among robot-assisted passive movements, voluntary active movements, and kinesthetic motor imagery. We measured and compared the brain activities of 21 young, healthy individuals during three experimental conditions associated with lower limb movements (active, passive, and imagery conditions) using functional near-infrared spectroscopy (fNIRS). Our results showed that although different brain areas with significant activity were observed among the conditions, the temporal patterns of the activity in each recording channel and the spatial patterns of functional connectivity showed high similarity between robot-assisted passive movements and voluntary active movements. Conversely, the robot-assisted passive movements did not show any similarity to motor imagery. Overall, these findings suggest that the robotic assistive approach is useful for activating not only afferent processes associated with sensory feedback processing but also motor control-related efferent processes. [ABSTRACT FROM AUTHOR]

Non-invasive brain stimulation using focused ultrasound has largely been carried out in small animals. In the present study, we applied stimulatory focused ultrasound transcranially to the primary sensorimotor (SM1) and visual (V1) brain areas in sheep (Dorset, all female, n = 8), under the guidance of magnetic resonance imaging, and examined the electrophysiologic responses. By use of a 250-kHz focused ultrasound transducer, the area was sonicated in pulsed mode (tone-burst duration of 1 ms, duty cycle of 50%) for 300 ms. The acoustic intensity at the focal target was varied up to a spatial peak pulse-average intensity (Isppa) of 14.3 W/cm(2). Sonication of SM1 elicited electromyographic responses from the contralateral hind leg, whereas stimulation of V1 generated electroencephalographic potentials. These responses were detected only above a certain acoustic intensity, and the threshold intensity, as well as the degree of responses, varied among sheep. Post-sonication animal behavior was normal, but minor microhemorrhages were observed from the V1 areas exposed to highly repetitive sonication (every second for ≥500 times for electroencephalographic measurements, Isppa = 6.6-10.5 W/cm(2), mechanical index = 0.9-1.2). Our results suggest the potential translational utility of focused ultrasound as a new brain stimulation modality, yet also call for caution in the use of an excessive number of sonications. [ABSTRACT FROM AUTHOR]

Vocal communication depends on the coordinated activity of sensorimotor neurons important to vocal perception and production. How vocalizations are represented by spatiotemporal activity patterns in these neuronal populations remains poorly understood. Here we combined intracellular recordings and two-photon calcium imaging in anesthetized adult zebra finches (Taeniopygia guttata) to examine how learned birdsong and its component syllables are represented in identified projection neurons (PNs) within HVC, a sensorimotor region important for song perception and production. These experiments show that neighboring HVC PNs can respond at markedly different times to song playback and that different syllables activate spatially intermingled PNs within a local (~ 100 μm) region of HVC. Moreover, noise correlations were stronger between PNs that responded most strongly to the same syllable and were spatially graded within and between classes of PNs. These findings support a model in which syllabic and temporal features of song are represented by spatially intermingled PNs functionally organized into cell- and syllable-type networks within local spatial scales in HVC. [ABSTRACT FROM AUTHOR]

Abstract: Background: Mutations in the THAP1 gene have recently been identified as the cause of DYT6 primary dystonia. However, the changes in THAP1 gene function and in the microstructure of brain white matter have not been well-characterized. Methods: Four different mutations of THAP1 expression (clones F22fs71X, C54F, F25fs53X, and L180S) were transfected into HEK-293T cells. The subcellular distribution of THAP1 in each clone was identified using immunofluorescence microscopy and Western blot. Six patients who harbored these THAP1 mutations underwent diffusion tensor magnetic resonance imaging (DTI) of the brain. The fractional anisotropy (FA) and mean diffusivity (MD) were measured in twenty-four regions of interest (ROI). Results: In two truncated mutations (F22fs71X and F25fs53X), the subcellular distribution of THAP1 were both in the cytoplasm and nucleus. However, the subcellular distribution was detected almost in the nucleus in two missense mutations (C54F and L180S). In the DTI maps, the average values of fractional anisotropy (FA), a measure of axonal integrity and coherence, was reduced (p < 0.005) in the subgyral white matter of the sensorimotor cortex of the DYT1 carriers, comparing with controls. Conclusions: Truncated THAP1 mutations (F22fs71X and F25fs53X) can alter the subcellular distributions, while some missense mutation (C54F and L180S) can not. The axonal integrity and coherence in the region of sensorimotor area of the brain was damaged in DYT6 dystonia. [Copyright &y& Elsevier]

Abstract: Objective: To determine the electrophysiological characteristics of frontotemporal dementia (FTD) and the distinction with Alzheimer’s disease (AD). Methods: We performed analyses of global field power (GFP) which is a measure of whole brain electric field strength, and EEG neuroimaging analyses with sLORETA (standardized low resolution electromagnetic tomography), in the mild stages of FTD (n =19; mean age=68.11±7.77) and AD (n =19; mean age=69.42±9.57) patients, and normal control (NC) subjects (n =22; mean age=66.13±6.02). Results: In the GFP analysis, significant group effects were observed in the delta (1.5–6.0Hz), alpha1 (8.5–10.0Hz), and beta1 (12.5–18.0Hz) bands. In sLORETA analysis, differences in activity were observed in the alpha1 band (NC>FTD) in the orbital frontal and temporal lobe, in the delta band (AD>NC) in widespread areas including the frontal lobe, and in the beta1 band (FTD>AD) in the parietal lobe and sensorimotor area. Conclusions: Differential patterns of brain regions and EEG frequency bands were observed between the FTD and AD groups in terms of pathological activity. Significance: FTD and AD patients in the early stages displayed different patterns in the cortical localization of oscillatory activity across different frequency bands. [Copyright &y& Elsevier]

Abstract: Central fatigue refers to a progressive decline in the ability to activate muscles voluntarily. Although the neural mechanisms of central inhibition of the motor area during physical fatigue have been widely investigated, mechanisms supporting motor output during fatigue remain to be clarified. In this study, the compensation mechanisms to regulate physical fatigue were examined using a 160-channel whole-head-type magnetoencephalographic (MEG) system. The study group consisted of nine right-handed healthy participants. After enrollment, participants performed a fatigue-inducing physical task session in which they performed repetitive grips of the right hand at maximal voluntary contraction levels every second. Before and after the session, imagery of maximum grips of the right hand was performed for evaluation with MEG. Although beta-band event-related desynchronization (ERD) level of the motor movement-evoked magnetic field in the left sensorimotor area showed a trend toward reduction after the fatigue session, the ERD level of the motor movement-evoked magnetic field in the right sensorimotor area was increased after the session. The ERD level in the prefrontal area was increased after the fatigue-inducing session. The ERD level in the left sensorimotor area was positively associated with that in the right sensorimotor area after the fatigue-inducing task session. In addition, ERD levels in the left and right sensorimotor areas had trends toward positive correlations with that in the prefrontal area. These results suggest that the ipsilateral sensorimotor and prefrontal areas are brain regions associated with compensation mechanisms to support motor output under the condition of physical fatigue. [Copyright &y& Elsevier]

Objective: Several findings support the concept that sensorimotor integration is disturbed in Parkinson's disease (PD) and in levodopa-induced dyskinesias. In this study, we explored the neuronal firing activity of excitatory pyramidal cells and inhibitory interneurons in the forelimb region of the primary somatosensory cortex (S1FL-Ctx), along with its interaction with oscillatory activity of the primary motor cortex (MCtx) in 6-hydroxydopamine lesioned hemiparkinsonian (HP) and levodopa-primed dyskinetic (HP-LID) rats as compared to controls. Further, gene expression patterns of distinct markers for inhibitory GABAergic neurons were analyzed in both cortical regions. Methods: Single unit activity and local field potential were recorded under urethane (1.4 g/kg, i.p) anesthesia by using quartz coated micro-electrode. Additionally, an electrocorticogram (ECoG) was acquired via a 1 mm diameter jeweller's screw, positioned on the dura mater above the MCtx ipsilateral to the 6-OHDA lesioned hemisphere. Results: While firing frequency and burst activity of S1FL-Ctx inhibitory interneurons were reduced in HP and HP-LID rats, measures of irregularity were enhanced in pyramidal cells. Further, enhanced coherence of distinct frequency bands of the theta/alpha, high-beta, and gamma frequency, together with enhanced synchronization of pyramidal cells and interneurons with MCtx oscillatory activity were observed. While GABA level was similar, gene expression levels of interneuron and GABAergic markers in S1FL-Ctx and MCtx of HP-LID rats differed to some extent. Conclusion: Our study shows both electrophysiological alterations and changes in gene expression in the sensorimotor cortices in a rat model of PD, which differ depending on the functional state after dopamine depletion and treatment indicating maladaptive neuroplasticity. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate the connectivity from the negative motor area and to elucidate the mechanism of negative motor phenomena. We report the results of cortico-cortical evoked potentials (CCEPs) by electrical stimulation of the primary motor area (MI), primary sensory area (SI), primary (PNMA) and supplementary negative motor area (SNMA) in eight epilepsy patients who underwent intracranial electrode placement. Alternating 1-Hz electrical stimuli were delivered to MI (six patients), SI (five), PNMA (six) and SNMA (two). CCEPs were recorded by averaging electrocorticograms time-locked to the stimuli. Stimulation of MI, SI and PNMA induced CCEP responses in the premotor area (PM), pre- and postcentral gyri, posterior parietal cortex and the temporo-parietal junction. Upon SNMA stimulation, CCEP responses were detected in the prefrontal cortex, PM, pre- and postcentral gyri, supplementary motor area (SMA) and preSMA. Compared with stimulation of SI and MI, PNMA stimulation revealed a broader distribution of CCEP responses in the frontal or parietal association cortex, indicating the importance of the fronto-parietal network associated with a higher level of motor control. We concluded that these connections are associated with motor control and that the negative motor phenomenon results from impairment of the organization of movements., (Copyright © 2012 Elsevier Ltd. All rights reserved.)