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Hartwig R Siebner - One of the best experts on this subject based on the ideXlab platform.
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does transcranial magnetic stimulation tms primarily target premotor or motor cortex in Precentral Gyrus
Clinical Neurophysiology, 2019Co-Authors: Raffaele Dubbioso, Peter Jagd Sorensen, Axel Thielscher, Hartwig R SiebnerAbstract:TMS can be used to map the corticomotor representations of hand muscles (HMs) in the Precentral Gyrus (PG), whose spatial peak is often not located in the primary motor hand area (M1HAND) but shifts towards the caudal part of dorsal premotor cortex (PMd). We used magnetic resonance imaging (MRI) to test the hypothesis that “hand-knob” of PG shows different structural properties in individuals with a “premotor” representation compared to individuals with a “primary-motor” representation of HMs. Twenty-four volunteers underwent MRI and sulcus-shape-based TMS-mapping of right PG. T1-weighted-MRIs were used for neuronavigation and to calculate cortical-thickness of the PG. We also performed quantitative multiparameter mapping of the longitudinal relaxation rate as an index of cortical myelination and simulated the electric field strength induced by TMS in the hand-knob-region. In 14 out-of 24 individuals (58%), TMS mapping disclosed a spatial peak in the PMd (“PMd-subjects”), whereas the remaining 10 subjects (42%) showed maximal motor response in M1HAND (“M1HAND-subjects”). “M1-subjects” displayed a higher electric field strength in the rostral part of the M1HAND (p = 0.01). “PMd-subjects” showed an increase of regional-myelination in the PG (p = 0.033). The results support the notion of two distinct functional-microstructural phenotypes of corticomotor hand representations in human PG.
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t122 does tms primarily target premotor or motor cortex in Precentral Gyrus
Clinical Neurophysiology, 2018Co-Authors: Raffaele Dubbioso, Peter Jagd Sorensen, Axel Thielscher, Hartwig R SiebnerAbstract:Introduction Transcranial magnetic stimulation (TMS) can be used to map the corticomotor representations of hand muscles in the Precentral Gyrus. The spatial peak of the corticomotor representations is often not located in the primary motor hand area (M1HAND), but shows an anterior shift towards the caudal part of dorsal premotor cortex (PMd). Here we used magnetic resonance imaging (MRI) to test the hypothesis that the “hand knob” of the Precentral Gyrus shows different structural properties in individuals with a clear “premotor” representation compared to individuals with a preponderant “primary-motor” representation of hand muscles. Methods Twenty-four volunteers (mean age: 24.3 ± 0.9 SE, 12 women) underwent whole-brain structural MRI and sulcus-shape based TMS mapping of the right Precentral Gyrus. High-resolution T1-weighted MRIs were used for neuronavigation of TMS and to calculate regional cortical thickness of the Precentral Gyrus. We also performed quantitative multiparameter mapping of the longitudinal relaxation rate (R1 = 1/T1) as an index of cortical myelination and simulated the electric field strength induced by TMS at motor threshold (—E—) in the hand-knob region (SimNIBS software). Sulcus-shape based TMS mapping was used to obtain mediolateral and posterior-anterior corticomotor excitability profiles of the left abductor digiti minimi and first dorsal interosseus muscles. Results In 14 out of 24 individuals (58%), TMS mapping disclosed a clear spatial peak in the PMd (referred to as “PMd” subjects”), whereas the remaining 10 subjects (42%) showed maximal motor responses more posteriorly in M1HAND (referred to as M1HAND subjects). Motor threshold was not different between the two groups (p = 0.265). Compared “PMd” subjects, “M1” subjects displayed a higher electric field strength in the very rostral part of the M1HAND in the transition zone from the wall to the crown of the Precentral Gyrus (p = 0.01). In addition, “PMd” subjects showed an overall increase of regional myelination in the Precentral Gyrus relative to the “M1” subjects (mixed model ANOVA: F(1,18) = 5.362, p = 0.033). No difference between two groups was evident for curvature and cortical thickness. Conclusion Differences in location of the “motor hot spot” are associated with differences in microstructure in the Precentral Gyrus and the magnitude of the induced electrical field. The results support the notion of two distinct functional and microstructural phenotypes of corticomotor hand representations in human Precentral Gyrus. They also underscore the usefulness of electrical field modelling to account for inter-individual differences in the biophysiological effects of TMS in the human brain.
Masayoshi Kurachi - One of the best experts on this subject based on the ideXlab platform.
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volumetric analysis of sulci gyri defined in vivo frontal lobe regions in schizophrenia Precentral Gyrus cingulate Gyrus and prefrontal region
Psychiatry Research-neuroimaging, 2005Co-Authors: Shiyu Zhou, Michio Suzuki, Hirofumi Hagino, Tsutomu Takahashi, Yasuhiro Kawasaki, Mie Matsui, Hikaru Seto, Masayoshi KurachiAbstract:Abstract Methodological limitations in most previous magnetic resonance imaging (MRI)-based volumetric studies might have contributed to the inconsistent results regarding the frontal lobe regions of schizophrenia. Thus, applying the largest sample to date among those that have fully taken account of the intrinsic anatomical landmarks, this study aimed at clarifying the volumetric alterations of the frontal lobe and its subregions in schizophrenia. Participants comprised 59 patients with schizophrenia and 58 healthy controls. Measurements were performed on consecutive 1-mm-thick coronal slices reformatted from three-dimensional 1.5-T MR images. The whole frontal lobe was demarcated and then subdivided into the Precentral Gyrus (PCG), anterior cingulate, and posterior cingulate, and the remainder temporarily as the prefrontal region. Patients with schizophrenia had significant cortical volume reductions in the bilateral whole frontal lobe, prefrontal region, PCG, posterior cingulate, and right anterior cingulate. This study has confirmed that patients with schizophrenia do have cortical volume reductions in the whole frontal lobe and its subregions. Volume reduction in the PCG suggests that the primary motor cortex might contribute to the mechanisms of schizophrenia, considering its important role in the processing of multiple motor-related cognitive functioning suggested by the recent literature.
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Volumetric analysis of sulci/gyri-defined in vivo frontal lobe regions in schizophrenia: Precentral Gyrus, cingulate Gyrus, and prefrontal region.
Psychiatry Research-neuroimaging, 2005Co-Authors: Shiyu Zhou, Michio Suzuki, Hirofumi Hagino, Tsutomu Takahashi, Yasuhiro Kawasaki, Mie Matsui, Hikaru Seto, Masayoshi KurachiAbstract:Abstract Methodological limitations in most previous magnetic resonance imaging (MRI)-based volumetric studies might have contributed to the inconsistent results regarding the frontal lobe regions of schizophrenia. Thus, applying the largest sample to date among those that have fully taken account of the intrinsic anatomical landmarks, this study aimed at clarifying the volumetric alterations of the frontal lobe and its subregions in schizophrenia. Participants comprised 59 patients with schizophrenia and 58 healthy controls. Measurements were performed on consecutive 1-mm-thick coronal slices reformatted from three-dimensional 1.5-T MR images. The whole frontal lobe was demarcated and then subdivided into the Precentral Gyrus (PCG), anterior cingulate, and posterior cingulate, and the remainder temporarily as the prefrontal region. Patients with schizophrenia had significant cortical volume reductions in the bilateral whole frontal lobe, prefrontal region, PCG, posterior cingulate, and right anterior cingulate. This study has confirmed that patients with schizophrenia do have cortical volume reductions in the whole frontal lobe and its subregions. Volume reduction in the PCG suggests that the primary motor cortex might contribute to the mechanisms of schizophrenia, considering its important role in the processing of multiple motor-related cognitive functioning suggested by the recent literature.
Xiaoli Li - One of the best experts on this subject based on the ideXlab platform.
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temporal changes in the expression of tgf beta 1 and egf in the ventral horn of the spinal cord and associated Precentral Gyrus in adult rhesus monkeys subjected to cord hemisection
Journal of the Neurological Sciences, 2008Co-Authors: Xiaoli Li, Xuyang Wang, Liyan Li, Wei Ni, Rongyuan Zheng, Huijuan Yang, Yongchao Lu, Jianguo Qi, Tinghua WangAbstract:Abstract It is well known that some growth factors can not only rescue neurons from death, but also improve motor functions following spinal cord injury. However, their cellular distribution in situ and temporal expressions following spinal cord injury have not been determined, especially in primates. This study investigated the temporal changes in the expression of two growth factors—epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-β1) in the injured motoneurons of the spinal cord and the associated Precentral Gyrus in adult Rhesus monkeys subjected to spinal cord hemisection. Animals were allowed to survive 7, 14, 30 and 90 days post operation (dpo). Functional recovery of the hindlimbs was assessed using Tarlov scale. The immunohistological expressions of EGF and TGF-β1 in the ventral horn motoneurons decreased sharply at 7 dpo in the cord segments caudal to the lesion site, which was followed by an increase and a peak between 14 and 30 dpo for EGF and at 90 dpo for TGF-β1. Changes in the expression of EGF in the Precentral Gyrus were similar to that in the spinal cord. No TGF-β1 immunoreactive neurons were detected in the Precentral Gyrus. In the spinal segments rostral to the lesion, the expressions of EGF and TGF-β1 peaked at 30 dpo. The mRNA of EGF was detected in both spinal motoneurons and the Precentral Gyrus, while that of TGF-β1, only in the spinal motoneuons, suggesting that the spinal motoneurons themselves could synthesize both the growth factors. Partial locomotor recovery in hindlimbs was seen, especially after 14 dpo. It was concluded that a possible association existed between the modulation of EGF and TGF-β1 and the recovery of locomotor function, and their roles differed somewhat in the neuroplasticity observed after spinal cord injury in primates.
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Temporal changes in the expression of TGF-beta 1 and EGF in the ventral horn of the spinal cord and associated Precentral Gyrus in adult Rhesus monkeys subjected to cord hemisection.
Journal of the neurological sciences, 2008Co-Authors: Xiaoli Li, Xuyang Wang, Liyan Li, Wei Ni, Rongyuan Zheng, Huijuan Yang, Yongchao Lu, Jianguo Qi, Tinghua WangAbstract:It is well known that some growth factors can not only rescue neurons from death, but also improve motor functions following spinal cord injury. However, their cellular distribution in situ and temporal expressions following spinal cord injury have not been determined, especially in primates. This study investigated the temporal changes in the expression of two growth factors--epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-beta1) in the injured motoneurons of the spinal cord and the associated Precentral Gyrus in adult Rhesus monkeys subjected to spinal cord hemisection. Animals were allowed to survive 7, 14, 30 and 90 days post operation (dpo). Functional recovery of the hindlimbs was assessed using Tarlov scale. The immunohistological expressions of EGF and TGF-beta1 in the ventral horn motoneurons decreased sharply at 7 dpo in the cord segments caudal to the lesion site, which was followed by an increase and a peak between 14 and 30 dpo for EGF and at 90 dpo for TGF-beta1. Changes in the expression of EGF in the Precentral Gyrus were similar to that in the spinal cord. No TGF-beta1 immunoreactive neurons were detected in the Precentral Gyrus. In the spinal segments rostral to the lesion, the expressions of EGF and TGF-beta1 peaked at 30 dpo. The mRNA of EGF was detected in both spinal motoneurons and the Precentral Gyrus, while that of TGF-beta1, only in the spinal motoneuons, suggesting that the spinal motoneurons themselves could synthesize both the growth factors. Partial locomotor recovery in hindlimbs was seen, especially after 14 dpo. It was concluded that a possible association existed between the modulation of EGF and TGF-beta1 and the recovery of locomotor function, and their roles differed somewhat in the neuroplasticity observed after spinal cord injury in primates.
Tinghua Wang - One of the best experts on this subject based on the ideXlab platform.
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temporal changes in the level of neurotrophins in the spinal cord and associated Precentral Gyrus following spinal hemisection in adult rhesus monkeys
Journal of Chemical Neuroanatomy, 2008Co-Authors: Hongtian Zhang, Yizhao Chen, Tinghua WangAbstract:Abstract Neurotrophins (NTs) appear to be crucial for the survival and potential regeneration of injured neurons. However, their temporal changes and remote regulations following spinal cord injury (SCI) have been only partially determined, especially in primates. In this study, ELISA was performed on the extracts of injured spinal cord and the associated Precentral Gyrus contralateral to the site of spinal cord hemisection to investigate the temporal changes in the levels of nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) in adult rhesus monkeys subjected to T8 spinal hemisection. Animals were allowed to survive 3, 7, 14, 30 and 90 days post-operation (dpo). In the spinal cord, the levels of NGF, BDNF and NT-3 sharply decreased between 3 and 7 dpo. Thereafter, the levels of NGF and BDNF were transiently elevated while NT-3 level continuously increased and recovered to normal level at 30 dpo. In the contralateral Precentral Gyrus (cPG), only the NT-3 level was altered and in fact elevated above the normal value. No obvious changes were observed in NT-4 level in any of the regions studied. Taken together, the present findings indicated that intrinsic NGF, BDNF and NT-3 may play a local role in the responses to the SCI in primates. Especially, the increase of NT-3 level occurred continuously in both the cPG and the spinal cord pointed to a possible transportation of NT-3 to the cord following SCI.
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temporal changes in the expression of tgf beta 1 and egf in the ventral horn of the spinal cord and associated Precentral Gyrus in adult rhesus monkeys subjected to cord hemisection
Journal of the Neurological Sciences, 2008Co-Authors: Xiaoli Li, Xuyang Wang, Liyan Li, Wei Ni, Rongyuan Zheng, Huijuan Yang, Yongchao Lu, Jianguo Qi, Tinghua WangAbstract:Abstract It is well known that some growth factors can not only rescue neurons from death, but also improve motor functions following spinal cord injury. However, their cellular distribution in situ and temporal expressions following spinal cord injury have not been determined, especially in primates. This study investigated the temporal changes in the expression of two growth factors—epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-β1) in the injured motoneurons of the spinal cord and the associated Precentral Gyrus in adult Rhesus monkeys subjected to spinal cord hemisection. Animals were allowed to survive 7, 14, 30 and 90 days post operation (dpo). Functional recovery of the hindlimbs was assessed using Tarlov scale. The immunohistological expressions of EGF and TGF-β1 in the ventral horn motoneurons decreased sharply at 7 dpo in the cord segments caudal to the lesion site, which was followed by an increase and a peak between 14 and 30 dpo for EGF and at 90 dpo for TGF-β1. Changes in the expression of EGF in the Precentral Gyrus were similar to that in the spinal cord. No TGF-β1 immunoreactive neurons were detected in the Precentral Gyrus. In the spinal segments rostral to the lesion, the expressions of EGF and TGF-β1 peaked at 30 dpo. The mRNA of EGF was detected in both spinal motoneurons and the Precentral Gyrus, while that of TGF-β1, only in the spinal motoneuons, suggesting that the spinal motoneurons themselves could synthesize both the growth factors. Partial locomotor recovery in hindlimbs was seen, especially after 14 dpo. It was concluded that a possible association existed between the modulation of EGF and TGF-β1 and the recovery of locomotor function, and their roles differed somewhat in the neuroplasticity observed after spinal cord injury in primates.
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Temporal changes in the expression of TGF-beta 1 and EGF in the ventral horn of the spinal cord and associated Precentral Gyrus in adult Rhesus monkeys subjected to cord hemisection.
Journal of the neurological sciences, 2008Co-Authors: Xiaoli Li, Xuyang Wang, Liyan Li, Wei Ni, Rongyuan Zheng, Huijuan Yang, Yongchao Lu, Jianguo Qi, Tinghua WangAbstract:It is well known that some growth factors can not only rescue neurons from death, but also improve motor functions following spinal cord injury. However, their cellular distribution in situ and temporal expressions following spinal cord injury have not been determined, especially in primates. This study investigated the temporal changes in the expression of two growth factors--epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-beta1) in the injured motoneurons of the spinal cord and the associated Precentral Gyrus in adult Rhesus monkeys subjected to spinal cord hemisection. Animals were allowed to survive 7, 14, 30 and 90 days post operation (dpo). Functional recovery of the hindlimbs was assessed using Tarlov scale. The immunohistological expressions of EGF and TGF-beta1 in the ventral horn motoneurons decreased sharply at 7 dpo in the cord segments caudal to the lesion site, which was followed by an increase and a peak between 14 and 30 dpo for EGF and at 90 dpo for TGF-beta1. Changes in the expression of EGF in the Precentral Gyrus were similar to that in the spinal cord. No TGF-beta1 immunoreactive neurons were detected in the Precentral Gyrus. In the spinal segments rostral to the lesion, the expressions of EGF and TGF-beta1 peaked at 30 dpo. The mRNA of EGF was detected in both spinal motoneurons and the Precentral Gyrus, while that of TGF-beta1, only in the spinal motoneuons, suggesting that the spinal motoneurons themselves could synthesize both the growth factors. Partial locomotor recovery in hindlimbs was seen, especially after 14 dpo. It was concluded that a possible association existed between the modulation of EGF and TGF-beta1 and the recovery of locomotor function, and their roles differed somewhat in the neuroplasticity observed after spinal cord injury in primates.
Raffaele Dubbioso - One of the best experts on this subject based on the ideXlab platform.
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does transcranial magnetic stimulation tms primarily target premotor or motor cortex in Precentral Gyrus
Clinical Neurophysiology, 2019Co-Authors: Raffaele Dubbioso, Peter Jagd Sorensen, Axel Thielscher, Hartwig R SiebnerAbstract:TMS can be used to map the corticomotor representations of hand muscles (HMs) in the Precentral Gyrus (PG), whose spatial peak is often not located in the primary motor hand area (M1HAND) but shifts towards the caudal part of dorsal premotor cortex (PMd). We used magnetic resonance imaging (MRI) to test the hypothesis that “hand-knob” of PG shows different structural properties in individuals with a “premotor” representation compared to individuals with a “primary-motor” representation of HMs. Twenty-four volunteers underwent MRI and sulcus-shape-based TMS-mapping of right PG. T1-weighted-MRIs were used for neuronavigation and to calculate cortical-thickness of the PG. We also performed quantitative multiparameter mapping of the longitudinal relaxation rate as an index of cortical myelination and simulated the electric field strength induced by TMS in the hand-knob-region. In 14 out-of 24 individuals (58%), TMS mapping disclosed a spatial peak in the PMd (“PMd-subjects”), whereas the remaining 10 subjects (42%) showed maximal motor response in M1HAND (“M1HAND-subjects”). “M1-subjects” displayed a higher electric field strength in the rostral part of the M1HAND (p = 0.01). “PMd-subjects” showed an increase of regional-myelination in the PG (p = 0.033). The results support the notion of two distinct functional-microstructural phenotypes of corticomotor hand representations in human PG.
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t122 does tms primarily target premotor or motor cortex in Precentral Gyrus
Clinical Neurophysiology, 2018Co-Authors: Raffaele Dubbioso, Peter Jagd Sorensen, Axel Thielscher, Hartwig R SiebnerAbstract:Introduction Transcranial magnetic stimulation (TMS) can be used to map the corticomotor representations of hand muscles in the Precentral Gyrus. The spatial peak of the corticomotor representations is often not located in the primary motor hand area (M1HAND), but shows an anterior shift towards the caudal part of dorsal premotor cortex (PMd). Here we used magnetic resonance imaging (MRI) to test the hypothesis that the “hand knob” of the Precentral Gyrus shows different structural properties in individuals with a clear “premotor” representation compared to individuals with a preponderant “primary-motor” representation of hand muscles. Methods Twenty-four volunteers (mean age: 24.3 ± 0.9 SE, 12 women) underwent whole-brain structural MRI and sulcus-shape based TMS mapping of the right Precentral Gyrus. High-resolution T1-weighted MRIs were used for neuronavigation of TMS and to calculate regional cortical thickness of the Precentral Gyrus. We also performed quantitative multiparameter mapping of the longitudinal relaxation rate (R1 = 1/T1) as an index of cortical myelination and simulated the electric field strength induced by TMS at motor threshold (—E—) in the hand-knob region (SimNIBS software). Sulcus-shape based TMS mapping was used to obtain mediolateral and posterior-anterior corticomotor excitability profiles of the left abductor digiti minimi and first dorsal interosseus muscles. Results In 14 out of 24 individuals (58%), TMS mapping disclosed a clear spatial peak in the PMd (referred to as “PMd” subjects”), whereas the remaining 10 subjects (42%) showed maximal motor responses more posteriorly in M1HAND (referred to as M1HAND subjects). Motor threshold was not different between the two groups (p = 0.265). Compared “PMd” subjects, “M1” subjects displayed a higher electric field strength in the very rostral part of the M1HAND in the transition zone from the wall to the crown of the Precentral Gyrus (p = 0.01). In addition, “PMd” subjects showed an overall increase of regional myelination in the Precentral Gyrus relative to the “M1” subjects (mixed model ANOVA: F(1,18) = 5.362, p = 0.033). No difference between two groups was evident for curvature and cortical thickness. Conclusion Differences in location of the “motor hot spot” are associated with differences in microstructure in the Precentral Gyrus and the magnitude of the induced electrical field. The results support the notion of two distinct functional and microstructural phenotypes of corticomotor hand representations in human Precentral Gyrus. They also underscore the usefulness of electrical field modelling to account for inter-individual differences in the biophysiological effects of TMS in the human brain.