BACKGROUND： Previous studies have demonstrated that appropriate interventions can alter brain electrical activity of epileptic patients prior to and during a seizure, leading to maintenance of a highly chaotic state,...BACKGROUND： Previous studies have demonstrated that appropriate interventions can alter brain electrical activity of epileptic patients prior to and during a seizure, leading to maintenance of a highly chaotic state, thereby inhibiting abnormal epileptic discharges, and eventually controlling epileptic seizure. OBJECTIVE： This study was designed to observe the effects of chaotic electrical stimulation to the subthalamic nucleus on mossy fiber sprouting, epileptic seizures, and electrical discharges, and to summarize the most suitable intervention. DESIGN, TIME AND SETTING： This randomized grouping, neuroelectrophysiological study was performed at the Laboratory of Neurology, Union Hospital Affiliated to Fujian Medical University in September 2007. MATERIALS： Fifty-five healthy, male, Sprague Dawley rats were subjected to an epileptic model by an intraperitoneal injection of pentylenetetrazol. The YC-2 programmed electrical stimulator was provided by Chengdu Instrument Factory, China; the video electroencephalographic system （KT-88-2400） and 24-hour active electroencephalographic system were products of Contec Medical System Co., Ltd., China; pentylenetetrazol was purchased from Sigma, USA. METHODS： The present interventional method consisted of electrical stimulation to the subthalamic nucleus with an intensity of 500 μA, pulse width 0.05 ms, frequency 30 Hz, and a duration of 20 minutes for 14 successive days. Fifty-five rats were divided into 6 groups： （1） pre-stimulation （n = 10）, pentylenetetrazol was administered and 30 minutes later, chaotic electrical stimulation was performed; （2） synchronous stimulation （n = 10）, rats received pentylenetetrazol and chaotic electrical stimulation concurrently; （3） post-administration stimulation （n = 10）, after pentylenetetrazol administration, chaotic electrical stimulation was performed immediately after cessation of a seizure; （4） sham-stimulation （n = 10）, following pentylenetetrazol administration, an electrode was connected to the stimulator, but electrical stimulation was not performed; （5） control （n = 10）, pentylenetetrazol administration, but no electrode was implanted; （6） blank control （n = 50）, administration of the same amount of physiological saline and chaotic electrical stimulation. MAIN OUTCOME MEASURES： Timm-stained granule change was scored. Simultaneously, electroencephalography was performed to acquire seizure counts and time course of epileptic discharge within 24 hours. RESULTS： Timm scores were lower in the electrically stimulated rats than in the non-stimulated rats （P 〈 0.01）. Timm scores were lowest in the synchronous stimulation group. When the rats suffered from tonic clonic seizure, the electroencephalogram primarily showed a persistent spike-slow wave and sharp wave. For the electrically stimulated rats, the mean values of seizure counts and time course of epileptic discharge during each hour were noticeably decreased compared with the non-stimulated rats. The synchronous stimulation group, however, had the lowest seizure counts and the shortest time course, followed by the pre-stimulation group, and lastly the post-administration stimulation group. Significant differences existed among the groups （P 〈 0.01）. Compared with the pre-stimulation group and the post-administration stimulation group, the latent period of grades Ⅰ and Ⅳ epileptic seizures was significantly prolonged, and the time course of tonic clonic seizure, as well as total time course, were significantly shortened in the synchronous stimulation group （P 〈 0.01）. CONCLUSION： Simultaneous administration of pentylenetetrazol together with chaotic electrical stimulation produced the greatest inhibitory effects on epileptic seizures. This is possibly related to inhibition of abnormal mossy fiber spouting in the hippocampus.展开更多
Malignant behaviors of brain gliomas include proliferation and infiltration.It remains unclear which behavior influences the status of adjacent corticospinal tracts.Diffusion tensor imaging can show the status of brai...Malignant behaviors of brain gliomas include proliferation and infiltration.It remains unclear which behavior influences the status of adjacent corticospinal tracts.Diffusion tensor imaging can show the status of brain white matter fiber tracts.Ki-67 and CD44/matrix metalloproteinase 9 are sensitive markers for reflecting the proliferation and infiltration of tumor cells.The present study analyzed pre-operative diffusion tensor images of 24 patients with pathologically confirmed World Health Organization glioma（Ⅰ-Ⅳ）.We observed lapse,infiltration and destruction of the peri-tumor corticospinal tract following reconstruction,and simultaneously detected the expression of Ki-67,CD44/matrix metalloproteinase 9 in samples.Expression of CD44 and matrix metalloproteinase 9was not significantly correlated to the status of the peri-tumor corticospinal tract（r = 1.597,4.859;P = 0.450,0.088）,while Ki-67 expression significantly correlated to its status（r= 6.590,P = 0.037）.These findings demonstrate that highly proliferative gliomas result in damage to the peripheral corticospinal tract.展开更多
Parkinson＇s disease is a progressive neurological disease characterized by the degeneration of dopaminergic neurons in the substantia nigra.A highly similar pattern of neurodegeneration can be induced by 1-methyl-4-p...Parkinson＇s disease is a progressive neurological disease characterized by the degeneration of dopaminergic neurons in the substantia nigra.A highly similar pattern of neurodegeneration can be induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP） or 1-methyl-4-phenylpyridinium ion（MPP＋）,which cause the death of dopaminergic neurons.Administration of MPTP or MPP＋ results in Parkinson＇s disease-like symptoms in rodents.However,it remains unclear whether intracerebroventricular MPP＋ administration affects neurogenesis in the substantia nigra and subgranular zone or whether brain-derived neurotrophic factor alters the effects of MPP＋.In this study,MPP＋（100 nmol） was intracerebroventricularly injected into mice to model Parkinson＇s disease.At 7 days after administration,the number of bromodeoxyuridine（Brd U）-positive cells in the subgranular zone of the hippocampal dentate gyrus increased,indicating enhanced neurogenesis.In contrast,a reduction in Brd U-positive cells was detected in the substantia nigra.Administration of brain-derived neurotrophic factor（100 ng） 1 day after MPP＋ administration attenuated the effect of MPP＋ in the subgranular zone and the substantia nigra.These findings reveal the complex interaction between neurotrophic factors and neurotoxins in the Parkinsonian model that result in distinct effects on the catecholaminergic system and on neurogenesis in different brain regions.展开更多
弥散磁共振成像(Diffusion magnetic resonance imaging,dMRI)作为一种先进的医学成像技术,能够在宏观层面上对活体大脑白质连接进行重建。该技术为量化描述大脑结构连接提供了重要的工具,能够使用连接性或者组织微观结构指标进行量化...弥散磁共振成像(Diffusion magnetic resonance imaging,dMRI)作为一种先进的医学成像技术,能够在宏观层面上对活体大脑白质连接进行重建。该技术为量化描述大脑结构连接提供了重要的工具,能够使用连接性或者组织微观结构指标进行量化分析。在过去的20年里,使用弥散磁共振纤维束成像研究大脑连接已经成为神经影像学研究的重要方向。纤维束成像分割则是在量化分析大脑连接时定义不同量化区域的关键,它能够识别对量化大脑结构连接有意义的白质通路,并实现跨受试者的白质通路的定量比较。本文对纤维束分割方法进行了回顾,并按其技术路线归纳为两大类:一类是针对特定解剖纤维束的分割方法,聚焦于具有明确结构定义的通路(如弓状束、锥体束),适用于任务导向型分析与临床导航;另一类是全脑纤维束分割方法,强调数据驱动或图谱导向的结构划分,用于构建大规模结构连接网络和开展全脑层级分析。此外,本文还探讨了各类方法在适用性、准确性、可重复性与计算成本等方面的权衡。尽管自动化分割技术近年来取得显著进展,但目前的方法仍然无法兼顾准确性、泛化性和效率,在解剖一致性、方法标准化及结果可解释性方面仍存在挑战。基于数据驱动的深度学习方法在纤维束分割领域迅速发展,表现出色,有望在上述方面取得更大突破。展开更多
基金Research and Development Foundation of Fujian Medical University, No. FJGXY04041
文摘BACKGROUND： Previous studies have demonstrated that appropriate interventions can alter brain electrical activity of epileptic patients prior to and during a seizure, leading to maintenance of a highly chaotic state, thereby inhibiting abnormal epileptic discharges, and eventually controlling epileptic seizure. OBJECTIVE： This study was designed to observe the effects of chaotic electrical stimulation to the subthalamic nucleus on mossy fiber sprouting, epileptic seizures, and electrical discharges, and to summarize the most suitable intervention. DESIGN, TIME AND SETTING： This randomized grouping, neuroelectrophysiological study was performed at the Laboratory of Neurology, Union Hospital Affiliated to Fujian Medical University in September 2007. MATERIALS： Fifty-five healthy, male, Sprague Dawley rats were subjected to an epileptic model by an intraperitoneal injection of pentylenetetrazol. The YC-2 programmed electrical stimulator was provided by Chengdu Instrument Factory, China; the video electroencephalographic system （KT-88-2400） and 24-hour active electroencephalographic system were products of Contec Medical System Co., Ltd., China; pentylenetetrazol was purchased from Sigma, USA. METHODS： The present interventional method consisted of electrical stimulation to the subthalamic nucleus with an intensity of 500 μA, pulse width 0.05 ms, frequency 30 Hz, and a duration of 20 minutes for 14 successive days. Fifty-five rats were divided into 6 groups： （1） pre-stimulation （n = 10）, pentylenetetrazol was administered and 30 minutes later, chaotic electrical stimulation was performed; （2） synchronous stimulation （n = 10）, rats received pentylenetetrazol and chaotic electrical stimulation concurrently; （3） post-administration stimulation （n = 10）, after pentylenetetrazol administration, chaotic electrical stimulation was performed immediately after cessation of a seizure; （4） sham-stimulation （n = 10）, following pentylenetetrazol administration, an electrode was connected to the stimulator, but electrical stimulation was not performed; （5） control （n = 10）, pentylenetetrazol administration, but no electrode was implanted; （6） blank control （n = 50）, administration of the same amount of physiological saline and chaotic electrical stimulation. MAIN OUTCOME MEASURES： Timm-stained granule change was scored. Simultaneously, electroencephalography was performed to acquire seizure counts and time course of epileptic discharge within 24 hours. RESULTS： Timm scores were lower in the electrically stimulated rats than in the non-stimulated rats （P 〈 0.01）. Timm scores were lowest in the synchronous stimulation group. When the rats suffered from tonic clonic seizure, the electroencephalogram primarily showed a persistent spike-slow wave and sharp wave. For the electrically stimulated rats, the mean values of seizure counts and time course of epileptic discharge during each hour were noticeably decreased compared with the non-stimulated rats. The synchronous stimulation group, however, had the lowest seizure counts and the shortest time course, followed by the pre-stimulation group, and lastly the post-administration stimulation group. Significant differences existed among the groups （P 〈 0.01）. Compared with the pre-stimulation group and the post-administration stimulation group, the latent period of grades Ⅰ and Ⅳ epileptic seizures was significantly prolonged, and the time course of tonic clonic seizure, as well as total time course, were significantly shortened in the synchronous stimulation group （P 〈 0.01）. CONCLUSION： Simultaneous administration of pentylenetetrazol together with chaotic electrical stimulation produced the greatest inhibitory effects on epileptic seizures. This is possibly related to inhibition of abnormal mossy fiber spouting in the hippocampus.
基金Anhui Prov-ince Grant of Tackle Key Problems in Science and Technology, No. 07010302202
文摘Malignant behaviors of brain gliomas include proliferation and infiltration.It remains unclear which behavior influences the status of adjacent corticospinal tracts.Diffusion tensor imaging can show the status of brain white matter fiber tracts.Ki-67 and CD44/matrix metalloproteinase 9 are sensitive markers for reflecting the proliferation and infiltration of tumor cells.The present study analyzed pre-operative diffusion tensor images of 24 patients with pathologically confirmed World Health Organization glioma（Ⅰ-Ⅳ）.We observed lapse,infiltration and destruction of the peri-tumor corticospinal tract following reconstruction,and simultaneously detected the expression of Ki-67,CD44/matrix metalloproteinase 9 in samples.Expression of CD44 and matrix metalloproteinase 9was not significantly correlated to the status of the peri-tumor corticospinal tract（r = 1.597,4.859;P = 0.450,0.088）,while Ki-67 expression significantly correlated to its status（r= 6.590,P = 0.037）.These findings demonstrate that highly proliferative gliomas result in damage to the peripheral corticospinal tract.
基金supported by the National Natural Science Foundation of China,No.31320103906(to TB)
文摘Parkinson＇s disease is a progressive neurological disease characterized by the degeneration of dopaminergic neurons in the substantia nigra.A highly similar pattern of neurodegeneration can be induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine（MPTP） or 1-methyl-4-phenylpyridinium ion（MPP＋）,which cause the death of dopaminergic neurons.Administration of MPTP or MPP＋ results in Parkinson＇s disease-like symptoms in rodents.However,it remains unclear whether intracerebroventricular MPP＋ administration affects neurogenesis in the substantia nigra and subgranular zone or whether brain-derived neurotrophic factor alters the effects of MPP＋.In this study,MPP＋（100 nmol） was intracerebroventricularly injected into mice to model Parkinson＇s disease.At 7 days after administration,the number of bromodeoxyuridine（Brd U）-positive cells in the subgranular zone of the hippocampal dentate gyrus increased,indicating enhanced neurogenesis.In contrast,a reduction in Brd U-positive cells was detected in the substantia nigra.Administration of brain-derived neurotrophic factor（100 ng） 1 day after MPP＋ administration attenuated the effect of MPP＋ in the subgranular zone and the substantia nigra.These findings reveal the complex interaction between neurotrophic factors and neurotoxins in the Parkinsonian model that result in distinct effects on the catecholaminergic system and on neurogenesis in different brain regions.
文摘弥散磁共振成像(Diffusion magnetic resonance imaging,dMRI)作为一种先进的医学成像技术,能够在宏观层面上对活体大脑白质连接进行重建。该技术为量化描述大脑结构连接提供了重要的工具,能够使用连接性或者组织微观结构指标进行量化分析。在过去的20年里,使用弥散磁共振纤维束成像研究大脑连接已经成为神经影像学研究的重要方向。纤维束成像分割则是在量化分析大脑连接时定义不同量化区域的关键,它能够识别对量化大脑结构连接有意义的白质通路,并实现跨受试者的白质通路的定量比较。本文对纤维束分割方法进行了回顾,并按其技术路线归纳为两大类:一类是针对特定解剖纤维束的分割方法,聚焦于具有明确结构定义的通路(如弓状束、锥体束),适用于任务导向型分析与临床导航;另一类是全脑纤维束分割方法,强调数据驱动或图谱导向的结构划分,用于构建大规模结构连接网络和开展全脑层级分析。此外,本文还探讨了各类方法在适用性、准确性、可重复性与计算成本等方面的权衡。尽管自动化分割技术近年来取得显著进展,但目前的方法仍然无法兼顾准确性、泛化性和效率,在解剖一致性、方法标准化及结果可解释性方面仍存在挑战。基于数据驱动的深度学习方法在纤维束分割领域迅速发展,表现出色,有望在上述方面取得更大突破。
