Hepatic encephalopathy(HE)is a neurological condition that occurs as a complication of liver dysfunction that involves sensorimotor symptoms in addition to cognitive and behavioral changes,particularly in cases of sev...Hepatic encephalopathy(HE)is a neurological condition that occurs as a complication of liver dysfunction that involves sensorimotor symptoms in addition to cognitive and behavioral changes,particularly in cases of severe liver disease or cirrhosis.Previous studies have reported spatially distributed structural and functional abnormalities related to HE,but the exact relationship between the structural and functional alterations with respect to disease progression remains unclear.In this study,we performed surface-based cortical thickness comparisons and functional connectivity(FC)analyses between three cross-sectional groups:healthy controls(HC,N¼51),patients with minimal hepatic en-cephalopathy(MHE,N¼50),patients with overt hepatic encephalopathy(OHE,N¼51).In addition to the distributed cortical thinning that is extensively thought to be associated with cognitive decline in HE,we found significant cortical thickening in the left para-hippocampal gyrus cortex in the OHE group(p<0.001,p¼0.009)as compared to the HC and MHE group respectively,which is further corroborated by the significant correlation between the cortical thickness and digit symbol test(DST)scores.Furthermore,the decreased FC between the right postcentral gyrus and several sensory regions(bilateral somatosensory and visual cortices)was found to be significant in MHE patients as compared to the HC group.Our results revealed cross-sectional structural and functional variations concerning disease progression across different subsystems(e.g.,visual,motor and sensory),providing evidence that can potentially explain the mechanisms underlying the sensorimotor and cognitive deficits related to HE.展开更多
Rhythm,as a prominent characteristic of auditory experiences such as speech and music,is known to facilitate attention,yet its contribution to working memory(WM)remains unclear.Here,human participants temporarily reta...Rhythm,as a prominent characteristic of auditory experiences such as speech and music,is known to facilitate attention,yet its contribution to working memory(WM)remains unclear.Here,human participants temporarily retained a 12-tone sequence presented rhythmically or arrhythmically in WM and performed a pitch change-detection task.Behaviorally,while having comparable accuracy,rhythmic tone sequences showed a faster response time and lower response boundaries in decision-making.Electroencephalographic recordings revealed that rhythmic sequences elicited enhanced non-phase-locked beta-band(16 Hz–33 Hz)and theta-band(3 Hz–5 Hz)neural oscillations during sensory encoding and WM retention periods,respectively.Importantly,the two-stage neural signatures were correlated with each other and contributed to behavior.As beta-band and theta-band oscillations denote the engagement of motor systems and WM maintenance,respectively,our findings imply that rhythm facilitates auditory WM through intricate oscillation-based interactions between the motor and auditory systems that facilitate predictive attention to auditory sequences.展开更多
Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral, unaffected sensorimotor cortex in a rat model of f...Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral, unaffected sensorimotor cortex in a rat model of focal cerebral infarct. The present study was designed to explore the mechanisms underlying improved motor function via transcranial magnetic stimulation and rehabilitation training following cerebral infarction. Results showed that rehabilitation training or transcranial magnetic stimulation alone reduced neurological impairment in rats following cerebral infarction, as well as significantly increased synaptic curvatures and post-synaptic density in the non-injured cerebral hemisphere sensorimotor cortex and narrowed the synapse cleft width. In addition, the percentage of perforated synapses increased. The combination of transcranial magnetic stimulation and rehabilitation resulted in significantly increased total dendritic length, dendritic branching points, and dendritic density in layer V pyramidal cells of the non-injured cerebral hemisphere motor cortex. These results demonstrated that transcranial magnetic stimulation and rehabilitation training altered structural parameters of pyramidal cell dendrites and synapses in the non-injured cerebral hemisphere sensorimotor cortex, thereby improving the ability to compensate for neurological functions in rats following cerebral infarction.展开更多
Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury（SCI）. The correlation between brain anatomical changes and fun...Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury（SCI）. The correlation between brain anatomical changes and functional reorganization after SCI is unclear. This study aimed to explore whether alterations of cortical structure and network function are concomitant in sensorimotor areas after incomplete SCI. Eighteen patients with incomplete SCI（mean age 40.94 ± 14.10 years old; male：female, 7：11） and 18 healthy subjects（37.33 ± 11.79 years old; male：female, 7：11） were studied by resting state functional magnetic resonance imaging. Gray matter volume（GMV） and functional connectivity were used to evaluate cortical structure and network function, respectively. There was no significant alteration of GMV in sensorimotor areas in patients with incomplete SCI compared with healthy subjects. Intra-hemispheric functional connectivity between left primary somatosensory cortex（BA1） and left primary motor cortex（BA4）, and left BA1 and left somatosensory association cortex（BA5） was decreased, as well as inter-hemispheric functional connectivity between left BA1 and right BA4, left BA1 and right BA5, and left BA4 and right BA5 in patients with SCI. Functional connectivity between both BA4 areas was also decreased. The decreased functional connectivity between the left BA1 and the right BA4 positively correlated with American Spinal Injury Association sensory score in SCI patients. The results indicate that alterations of cortical anatomical structure and network functional connectivity in sensorimotor areas were non-concomitant in patients with incomplete SCI, indicating the network functional changes in sensorimotor areas may not be dependent on anatomic structure. The strength of functional connectivity within sensorimotor areas could serve as a potential imaging biomarker for assessment and prediction of sensory function in patients with incomplete SCI. This trial was registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-ROC-17013566）.展开更多
The deep cerebellar nuclei(DCN)integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning.However,the functional relevance of distinct neuronal subp...The deep cerebellar nuclei(DCN)integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning.However,the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood.Here,we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial(Vm)thalamus(DCNVm neurons),and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning(tEBC),a classical associative sensorimotor learning task.Upon conditioning,the activity of DCNVm neurons signaled the performance of conditioned eyeblink responses(CRs).Optogenetic activation and inhibition of the DCNVm neurons in well-trained mice amplified and diminished the CRs,respectively.Chemogenetic manipulation of the DCNVm neurons had no effects on non-associative motor coordination.Furthermore,optogenetic activation of the DCNVm neurons caused rapid elevated firing activity in the cingulate cortex,a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC.Together,our data highlights DCNVm neurons’function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.展开更多
Perceiving pitch is a central function of the human auditory system;congenital amusia is a disorder of pitch perception.The underlying neural mechanisms of congenital amusia have been actively discussed.However,little...Perceiving pitch is a central function of the human auditory system;congenital amusia is a disorder of pitch perception.The underlying neural mechanisms of congenital amusia have been actively discussed.However,little attention has been paid to the changes in the motor rain within congenital amusia.In this case-control study,17 participants with congenital amusia and 14 healthy controls underwent functional magnetic resonance imaging while resting with their eyes closed.A voxel-based degree centrality method was used to identify abnormal functional network centrality by comparing degree centrality values between the congenital amusia group and the healthy control group.We found decreased degree centrality values in the right primary sensorimotor areas in participants with congenital amusia relative to controls,indicating potentially decreased centrality of the corresponding brain regions in the auditory-sensory motor feedback network.We found a significant positive correlation between the degree centrality values and the Montreal Battery of Evaluation of Amusia scores.In conclusion,our study identified novel,hitherto undiscussed candidate brain regions that may partly contribute to or be modulated by congenital amusia.Our evidence supports the view that sensorimotor coupling plays an important role in memory and musical discrimination.The study was approved by the Ethics Committee of the Second Xiangya Hospital,Central South University,China(No.WDX20180101GZ01)on February 9,2019.展开更多
Mice subjected to an irregular light-dark cycle are known to lose their capacity to synchronize their behavioral rhythm to environmental light, and to show endophenotypes related to depressive disorders. Here we obser...Mice subjected to an irregular light-dark cycle are known to lose their capacity to synchronize their behavioral rhythm to environmental light, and to show endophenotypes related to depressive disorders. Here we observed that a susceptible strain of mice (C3H/HeJ) subjected to an irregular 3.5 hr:3.5 hr light-dark cycle showed an enhanced acoustic startle reflex and deficits in prepulse inhibition. As impaired sensorimotor gating is associated with the onset of a variety of mental disorders such as schizophrenia and major depressive disorder, irregular environmental light without circadian photo-entrainment may cause stress that has the potential to be involved in humans’ susceptibility to neuropsychiatric abnormalities.展开更多
基金the National Natural Scientific Foundation of China(82071994,82202249)Tianjin Health High Level Talent Selection and Training Project(TJSQNYXXR-D2-143)+4 种基金Natural Scientific Foundation of Tianjin(21CYBJC01580,21JCQNJC01480)Tianjin Health Research Project(TJWJ2023QN031,TJWJ2023XK012)Tianjin Health Science and technology project(Specific projects of key disciplines)(TJWJ2022XK019)Tianjin Key Medical Discipline(Specialty)Construction Project(TJYXZDXK-041A)Tianjin Natural Science Foundation(21JCYBJC01290).
文摘Hepatic encephalopathy(HE)is a neurological condition that occurs as a complication of liver dysfunction that involves sensorimotor symptoms in addition to cognitive and behavioral changes,particularly in cases of severe liver disease or cirrhosis.Previous studies have reported spatially distributed structural and functional abnormalities related to HE,but the exact relationship between the structural and functional alterations with respect to disease progression remains unclear.In this study,we performed surface-based cortical thickness comparisons and functional connectivity(FC)analyses between three cross-sectional groups:healthy controls(HC,N¼51),patients with minimal hepatic en-cephalopathy(MHE,N¼50),patients with overt hepatic encephalopathy(OHE,N¼51).In addition to the distributed cortical thinning that is extensively thought to be associated with cognitive decline in HE,we found significant cortical thickening in the left para-hippocampal gyrus cortex in the OHE group(p<0.001,p¼0.009)as compared to the HC and MHE group respectively,which is further corroborated by the significant correlation between the cortical thickness and digit symbol test(DST)scores.Furthermore,the decreased FC between the right postcentral gyrus and several sensory regions(bilateral somatosensory and visual cortices)was found to be significant in MHE patients as compared to the HC group.Our results revealed cross-sectional structural and functional variations concerning disease progression across different subsystems(e.g.,visual,motor and sensory),providing evidence that can potentially explain the mechanisms underlying the sensorimotor and cognitive deficits related to HE.
基金supported by the National Natural Science Foundation of China(12171373)supported by the Fundamental Research Funds for the Central Universities of China(GK202207018).
文摘Rhythm,as a prominent characteristic of auditory experiences such as speech and music,is known to facilitate attention,yet its contribution to working memory(WM)remains unclear.Here,human participants temporarily retained a 12-tone sequence presented rhythmically or arrhythmically in WM and performed a pitch change-detection task.Behaviorally,while having comparable accuracy,rhythmic tone sequences showed a faster response time and lower response boundaries in decision-making.Electroencephalographic recordings revealed that rhythmic sequences elicited enhanced non-phase-locked beta-band(16 Hz–33 Hz)and theta-band(3 Hz–5 Hz)neural oscillations during sensory encoding and WM retention periods,respectively.Importantly,the two-stage neural signatures were correlated with each other and contributed to behavior.As beta-band and theta-band oscillations denote the engagement of motor systems and WM maintenance,respectively,our findings imply that rhythm facilitates auditory WM through intricate oscillation-based interactions between the motor and auditory systems that facilitate predictive attention to auditory sequences.
基金Yantai Science and Technology Development Projects, No. 2008142-5
文摘Very little is known about the effects of transcranial magnetic stimulation and rehabilitation training on pyramidal cell dendrites and synapses of the contralateral, unaffected sensorimotor cortex in a rat model of focal cerebral infarct. The present study was designed to explore the mechanisms underlying improved motor function via transcranial magnetic stimulation and rehabilitation training following cerebral infarction. Results showed that rehabilitation training or transcranial magnetic stimulation alone reduced neurological impairment in rats following cerebral infarction, as well as significantly increased synaptic curvatures and post-synaptic density in the non-injured cerebral hemisphere sensorimotor cortex and narrowed the synapse cleft width. In addition, the percentage of perforated synapses increased. The combination of transcranial magnetic stimulation and rehabilitation resulted in significantly increased total dendritic length, dendritic branching points, and dendritic density in layer V pyramidal cells of the non-injured cerebral hemisphere motor cortex. These results demonstrated that transcranial magnetic stimulation and rehabilitation training altered structural parameters of pyramidal cell dendrites and synapses in the non-injured cerebral hemisphere sensorimotor cortex, thereby improving the ability to compensate for neurological functions in rats following cerebral infarction.
基金supported by a grant from Tsinghua University Initiative Scientific Research Program,No.2014081266,20131089382the National Natural Science Foundation of China,No.61171002,60372023
文摘Brain plasticity, including anatomical changes and functional reorganization, is the physiological basis of functional recovery after spinal cord injury（SCI）. The correlation between brain anatomical changes and functional reorganization after SCI is unclear. This study aimed to explore whether alterations of cortical structure and network function are concomitant in sensorimotor areas after incomplete SCI. Eighteen patients with incomplete SCI（mean age 40.94 ± 14.10 years old; male：female, 7：11） and 18 healthy subjects（37.33 ± 11.79 years old; male：female, 7：11） were studied by resting state functional magnetic resonance imaging. Gray matter volume（GMV） and functional connectivity were used to evaluate cortical structure and network function, respectively. There was no significant alteration of GMV in sensorimotor areas in patients with incomplete SCI compared with healthy subjects. Intra-hemispheric functional connectivity between left primary somatosensory cortex（BA1） and left primary motor cortex（BA4）, and left BA1 and left somatosensory association cortex（BA5） was decreased, as well as inter-hemispheric functional connectivity between left BA1 and right BA4, left BA1 and right BA5, and left BA4 and right BA5 in patients with SCI. Functional connectivity between both BA4 areas was also decreased. The decreased functional connectivity between the left BA1 and the right BA4 positively correlated with American Spinal Injury Association sensory score in SCI patients. The results indicate that alterations of cortical anatomical structure and network functional connectivity in sensorimotor areas were non-concomitant in patients with incomplete SCI, indicating the network functional changes in sensorimotor areas may not be dependent on anatomic structure. The strength of functional connectivity within sensorimotor areas could serve as a potential imaging biomarker for assessment and prediction of sensory function in patients with incomplete SCI. This trial was registered with the Chinese Clinical Trial Registry（registration number： Chi CTR-ROC-17013566）.
基金This work was supported by grants from the National Natural Science Foundation of China(81871039)the Natural Science Foundation of Chongqing Municipality(cstc2019jcyj-msxmX0424)+1 种基金the Frontier Interdisciplinary Project of the College of Basic Sciences(2020JCZX02)the Special Training Program for Undergraduates of Army Medical University(2020XBK09 and 2021XBK45).
文摘The deep cerebellar nuclei(DCN)integrate various inputs to the cerebellum and form the final cerebellar outputs critical for associative sensorimotor learning.However,the functional relevance of distinct neuronal subpopulations within the DCN remains poorly understood.Here,we examined a subpopulation of mouse DCN neurons whose axons specifically project to the ventromedial(Vm)thalamus(DCNVm neurons),and found that these neurons represent a specific subset of DCN units whose activity varies with trace eyeblink conditioning(tEBC),a classical associative sensorimotor learning task.Upon conditioning,the activity of DCNVm neurons signaled the performance of conditioned eyeblink responses(CRs).Optogenetic activation and inhibition of the DCNVm neurons in well-trained mice amplified and diminished the CRs,respectively.Chemogenetic manipulation of the DCNVm neurons had no effects on non-associative motor coordination.Furthermore,optogenetic activation of the DCNVm neurons caused rapid elevated firing activity in the cingulate cortex,a brain area critical for bridging the time gap between sensory stimuli and motor execution during tEBC.Together,our data highlights DCNVm neurons’function and delineates their kinematic parameters that modulate the strength of associative sensorimotor responses.
基金the National Natural Science Foundation of China(No.61375086)the Key Project of Science and Technique Plan of Beijing Municipal Commission of Education(No.KZ201210005001)+1 种基金the National Basic Research Program(973)of China(No.2012CB720000)the China Scholarship Council Program(No.201406540017)
基金supported by the National Natural Science Foundation of China,No.81771172(to DXW),81671671(to JL)the Second Xiangya Hospital Start-Up Fund,China。
文摘Perceiving pitch is a central function of the human auditory system;congenital amusia is a disorder of pitch perception.The underlying neural mechanisms of congenital amusia have been actively discussed.However,little attention has been paid to the changes in the motor rain within congenital amusia.In this case-control study,17 participants with congenital amusia and 14 healthy controls underwent functional magnetic resonance imaging while resting with their eyes closed.A voxel-based degree centrality method was used to identify abnormal functional network centrality by comparing degree centrality values between the congenital amusia group and the healthy control group.We found decreased degree centrality values in the right primary sensorimotor areas in participants with congenital amusia relative to controls,indicating potentially decreased centrality of the corresponding brain regions in the auditory-sensory motor feedback network.We found a significant positive correlation between the degree centrality values and the Montreal Battery of Evaluation of Amusia scores.In conclusion,our study identified novel,hitherto undiscussed candidate brain regions that may partly contribute to or be modulated by congenital amusia.Our evidence supports the view that sensorimotor coupling plays an important role in memory and musical discrimination.The study was approved by the Ethics Committee of the Second Xiangya Hospital,Central South University,China(No.WDX20180101GZ01)on February 9,2019.
文摘Mice subjected to an irregular light-dark cycle are known to lose their capacity to synchronize their behavioral rhythm to environmental light, and to show endophenotypes related to depressive disorders. Here we observed that a susceptible strain of mice (C3H/HeJ) subjected to an irregular 3.5 hr:3.5 hr light-dark cycle showed an enhanced acoustic startle reflex and deficits in prepulse inhibition. As impaired sensorimotor gating is associated with the onset of a variety of mental disorders such as schizophrenia and major depressive disorder, irregular environmental light without circadian photo-entrainment may cause stress that has the potential to be involved in humans’ susceptibility to neuropsychiatric abnormalities.
