Evidences show that electric fields(EFs)induced by the magnetic stimulation could modulates brain activities by regulating the excitability of GABAergic interneuron.However,it is still unclear how and why the EF-induc...Evidences show that electric fields(EFs)induced by the magnetic stimulation could modulates brain activities by regulating the excitability of GABAergic interneuron.However,it is still unclear how and why the EF-induced polarization affects the interneuron response as the interneuron receives NMDA synaptic inputs.Considering the key role of NMDA receptor-mediated supralinear dendritic integration in neuronal computations,we suppose that the applied EFs could functionally modulate interneurons’response via regulating dendritic integration.At first,we build a simplified multi-dendritic circuit model with inhomogeneous extracellular potentials,which characterizes the relationship among EF-induced spatial polarizations,dendritic integration,and somatic output.By performing model-based singular perturbation analysis,it is found that the equilibrium point of fast subsystem can be used to asymptotically depict the subthreshold input–output(sI/O)relationship of dendritic integration.It predicted that EF-induced strong depolarizations on the distal dendrites reduce the dendritic saturation output by reducing driving force of synaptic input,and it shifts the steep change of sI/O curve left by reducing stimulation threshold of triggering NMDA spike.Also,the EF modulation prefers the global dendritic integration with asymmetric scatter distribution of NMDA synapses.Furthermore,we identify the respective contribution of EF-regulated dendritic integration and EF-induced somatic polarization to an action potential generation and find that they have an antagonistic effect on AP generation due to the varied NMDA spike threshold under EF stimulation.展开更多
The back-propagating action potential(bpAP)is crucial for neuronal signal integration and synaptic plasticity in dendritic trees.Its properties(velocity and amplitude)can be affected by dendritic morphology.Due to lim...The back-propagating action potential(bpAP)is crucial for neuronal signal integration and synaptic plasticity in dendritic trees.Its properties(velocity and amplitude)can be affected by dendritic morphology.Due to limited spatial resolution,it has been difficult to explore the specific propagation process of bpAPs along dendrites and examine the influence of dendritic morphology,such as the dendrite diameter and branching pattern,using patch-clamp recording.By taking advantage of Optopatch,an all-optical electrophysiological method,we made detailed recordings of the real-time propagation of bpAPs in dendritic trees.We found that the velocity of bpAPs was not uniform in a single dendrite,and the bpAP velocity differed among distinct dendrites of the same neuron.The velocity of a bpAP was positively correlated with the diameter of the dendrite on which it propagated.In addition,when bpAPs passed through a dendritic branch point,their velocity decreased significantly.Similar to velocity,the amplitude of bpAPs was also positively correlated with dendritic diameter,and the attenuation patterns of bpAPs differed among different dendrites.Simulation results from neuron models with different dendritic morphology corresponded well with the experimental results.These findings indicate that the dendritic diameter and branching pattern significantly influence the properties of bpAPs.The diversity among the bpAPs recorded in different neurons was mainly due to differences in dendritic morphology.These results may inspire the construction of neuronal models to predict the propagation of bpAPs in dendrites with enormous variation in morphology,to further illuminate the role of bpAPs in neuronal communication.展开更多
Li metal is considered an ideal anode material for application in the next-generation secondary batteries.However,the commercial application of Li metal batteries has not yet been achieved due to the safety concern ca...Li metal is considered an ideal anode material for application in the next-generation secondary batteries.However,the commercial application of Li metal batteries has not yet been achieved due to the safety concern caused by Li dendrites growth.Despite the fact that many recent experimental studies found that external pressure suppresses the Li dendrites growth,the mechanism of the external pressure effect on Li dendrites remains poorly understood on the atomic scale.Herein,the large-scale molecular dynamics simulations of Li dendrites growth under different external pressure were performed with a machine learning potential,which has the quantum-mechanical accuracy.The simulation results reveal that the external pressure promotes the process of Li self-healing.With the increase of external pressure,the hole defects and Li dendrites would gradually fuse and disappear.This work provides a new perspective for understanding the mechanism for the impact of external pressure on Li dendrites.展开更多
Objective To explore the role of lung dendritic cells(DCs) and Th17 /regulatory T cells ( Treg) pathway inthe pathogenesis of chronic obstructive pulmonary disease(COPD). Methods COPD patients who received lobectomyfr...Objective To explore the role of lung dendritic cells(DCs) and Th17 /regulatory T cells ( Treg) pathway inthe pathogenesis of chronic obstructive pulmonary disease(COPD). Methods COPD patients who received lobectomyfrom Sep. 2015 to Mar. 2016 in our hospital wereenrolled and classified into non-smoking non-COPDgroup,smoking without COPD group and COPD group.The expression of CD80,chemokine recepter-6 (CCR6),interleukin-17A ( IL-17A) and fork-head transcriptionfactor P3 (FoxP3) were detected by immunohistochemistry(IHC) in lung tissue. Mature DCs (mDCs),immatureDCs ( imDCs),Th17 cells and Treg cells in lungtissue were detected by flow cytometry ( FCM) and thecorrelation between Th17 /Treg cells with lung functionwas analyzed. Results (1) The expression of CD80 andFoxP3 in COPD group was decreased,while the expressionof CCR6 and IL-17A was increased (P < 0. 05).展开更多
Our general understanding of the function of neurons is that dendrites receive information that is relayed to the axon, where action potentials are initiated and propagated to eventually trigger neurotransmitter relea...Our general understanding of the function of neurons is that dendrites receive information that is relayed to the axon, where action potentials are initiated and propagated to eventually trigger neurotransmitter release at synaptic terminals. Although for a number of neuron types in the mammalian brain, many neuron types do not follow this classical polarity pattern. In fact, dendrites may be the site of action potentials initiation and propagation. It should be noted that convincing evidence has been obtained for the existence of dendritic action potentials in hippocampal and neocortical neurons. With regard to the dendrite potentials of thalamic neurons in general and specifically the reticular nucleus of the thalamus, it has not yet been reported. The results of this study demonstrate, for the first time, that generation of spike potentials of different amplitudes was observed in the activity of the thalamic reticular nucleus neurons. The generation of one action potential does not interfere with the generation of another, and a spike potential of smaller amplitude can occur at the ascending or descending phase of the spike potential of large amplitude. It can be argued that the spike potentials of lower amplitudes arising in the thalamic reticular nucleus neuron are of dendrite origin. Given both the strategic position and the functional purpose of the TRN, it can be assumed that the neurons of this structure must each time be discharged with spike potentials in order to carry out their modulating effect on other areas of the nervous system of the brain without leakage.展开更多
AIM: To investigate whether in the prefrontal cortical(PFC) pyramidal eells, focal glutamate application tothe apical dendrite induces bursting and whether theeffect of glutamate involves activation of both NMDAand no...AIM: To investigate whether in the prefrontal cortical(PFC) pyramidal eells, focal glutamate application tothe apical dendrite induces bursting and whether theeffect of glutamate involves activation of both NMDAand non-NMDA receptors. METHODS: Pyramidalcells in layers Ⅴ and Ⅵ of the PFC were visualized inrat brain slices using infrared videomicroscopy andrecorded with whole-cell electrodes. Glutamate and itsagonists were focally applied to the apical dendrite andthe soma using microiontophoresis. RESULTS:Dendritic glutamate application (0--20 nA, 10 mmol/L) induced repetitive bursts in most cells tested (12/展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.62171312)the Tianjin Municipal Education Commission Scientific Research Project,China(Grant No.2020KJ114).
文摘Evidences show that electric fields(EFs)induced by the magnetic stimulation could modulates brain activities by regulating the excitability of GABAergic interneuron.However,it is still unclear how and why the EF-induced polarization affects the interneuron response as the interneuron receives NMDA synaptic inputs.Considering the key role of NMDA receptor-mediated supralinear dendritic integration in neuronal computations,we suppose that the applied EFs could functionally modulate interneurons’response via regulating dendritic integration.At first,we build a simplified multi-dendritic circuit model with inhomogeneous extracellular potentials,which characterizes the relationship among EF-induced spatial polarizations,dendritic integration,and somatic output.By performing model-based singular perturbation analysis,it is found that the equilibrium point of fast subsystem can be used to asymptotically depict the subthreshold input–output(sI/O)relationship of dendritic integration.It predicted that EF-induced strong depolarizations on the distal dendrites reduce the dendritic saturation output by reducing driving force of synaptic input,and it shifts the steep change of sI/O curve left by reducing stimulation threshold of triggering NMDA spike.Also,the EF modulation prefers the global dendritic integration with asymmetric scatter distribution of NMDA synapses.Furthermore,we identify the respective contribution of EF-regulated dendritic integration and EF-induced somatic polarization to an action potential generation and find that they have an antagonistic effect on AP generation due to the varied NMDA spike threshold under EF stimulation.
基金the National Science and Technology Innovation 2030-Major program of"Brain Science and Brain-Like Research"(2022ZD0211800)the National Natural Science Foundation of China(81971679,32020103007,32088101,and 21727806),the Ministry of Science and Technology(2018YFA0507600 and2017YFA0503600)+1 种基金theQidong-PKU SLS Innovation Fund(2016000663 and 2017000246)the National Key R&DProgram of China(2020AAA0105200).
文摘The back-propagating action potential(bpAP)is crucial for neuronal signal integration and synaptic plasticity in dendritic trees.Its properties(velocity and amplitude)can be affected by dendritic morphology.Due to limited spatial resolution,it has been difficult to explore the specific propagation process of bpAPs along dendrites and examine the influence of dendritic morphology,such as the dendrite diameter and branching pattern,using patch-clamp recording.By taking advantage of Optopatch,an all-optical electrophysiological method,we made detailed recordings of the real-time propagation of bpAPs in dendritic trees.We found that the velocity of bpAPs was not uniform in a single dendrite,and the bpAP velocity differed among distinct dendrites of the same neuron.The velocity of a bpAP was positively correlated with the diameter of the dendrite on which it propagated.In addition,when bpAPs passed through a dendritic branch point,their velocity decreased significantly.Similar to velocity,the amplitude of bpAPs was also positively correlated with dendritic diameter,and the attenuation patterns of bpAPs differed among different dendrites.Simulation results from neuron models with different dendritic morphology corresponded well with the experimental results.These findings indicate that the dendritic diameter and branching pattern significantly influence the properties of bpAPs.The diversity among the bpAPs recorded in different neurons was mainly due to differences in dendritic morphology.These results may inspire the construction of neuronal models to predict the propagation of bpAPs in dendrites with enormous variation in morphology,to further illuminate the role of bpAPs in neuronal communication.
基金supported by the National Natural Science Foundation of China(No.52272180,No.12174162,No.51962010)the Shenzhen Science and Technology Research Grant(No.20220810123501001)the IER Foundation 2021(IERF202104)。
文摘Li metal is considered an ideal anode material for application in the next-generation secondary batteries.However,the commercial application of Li metal batteries has not yet been achieved due to the safety concern caused by Li dendrites growth.Despite the fact that many recent experimental studies found that external pressure suppresses the Li dendrites growth,the mechanism of the external pressure effect on Li dendrites remains poorly understood on the atomic scale.Herein,the large-scale molecular dynamics simulations of Li dendrites growth under different external pressure were performed with a machine learning potential,which has the quantum-mechanical accuracy.The simulation results reveal that the external pressure promotes the process of Li self-healing.With the increase of external pressure,the hole defects and Li dendrites would gradually fuse and disappear.This work provides a new perspective for understanding the mechanism for the impact of external pressure on Li dendrites.
文摘Objective To explore the role of lung dendritic cells(DCs) and Th17 /regulatory T cells ( Treg) pathway inthe pathogenesis of chronic obstructive pulmonary disease(COPD). Methods COPD patients who received lobectomyfrom Sep. 2015 to Mar. 2016 in our hospital wereenrolled and classified into non-smoking non-COPDgroup,smoking without COPD group and COPD group.The expression of CD80,chemokine recepter-6 (CCR6),interleukin-17A ( IL-17A) and fork-head transcriptionfactor P3 (FoxP3) were detected by immunohistochemistry(IHC) in lung tissue. Mature DCs (mDCs),immatureDCs ( imDCs),Th17 cells and Treg cells in lungtissue were detected by flow cytometry ( FCM) and thecorrelation between Th17 /Treg cells with lung functionwas analyzed. Results (1) The expression of CD80 andFoxP3 in COPD group was decreased,while the expressionof CCR6 and IL-17A was increased (P < 0. 05).
文摘Our general understanding of the function of neurons is that dendrites receive information that is relayed to the axon, where action potentials are initiated and propagated to eventually trigger neurotransmitter release at synaptic terminals. Although for a number of neuron types in the mammalian brain, many neuron types do not follow this classical polarity pattern. In fact, dendrites may be the site of action potentials initiation and propagation. It should be noted that convincing evidence has been obtained for the existence of dendritic action potentials in hippocampal and neocortical neurons. With regard to the dendrite potentials of thalamic neurons in general and specifically the reticular nucleus of the thalamus, it has not yet been reported. The results of this study demonstrate, for the first time, that generation of spike potentials of different amplitudes was observed in the activity of the thalamic reticular nucleus neurons. The generation of one action potential does not interfere with the generation of another, and a spike potential of smaller amplitude can occur at the ascending or descending phase of the spike potential of large amplitude. It can be argued that the spike potentials of lower amplitudes arising in the thalamic reticular nucleus neuron are of dendrite origin. Given both the strategic position and the functional purpose of the TRN, it can be assumed that the neurons of this structure must each time be discharged with spike potentials in order to carry out their modulating effect on other areas of the nervous system of the brain without leakage.
基金Scottish Rite Benevolent Foundation's Schizophrenia Research Program (Shi WX)a NASARD Young Investigator Award (Shi WX)an USPHS grant MH52686(shi WX)
文摘AIM: To investigate whether in the prefrontal cortical(PFC) pyramidal eells, focal glutamate application tothe apical dendrite induces bursting and whether theeffect of glutamate involves activation of both NMDAand non-NMDA receptors. METHODS: Pyramidalcells in layers Ⅴ and Ⅵ of the PFC were visualized inrat brain slices using infrared videomicroscopy andrecorded with whole-cell electrodes. Glutamate and itsagonists were focally applied to the apical dendrite andthe soma using microiontophoresis. RESULTS:Dendritic glutamate application (0--20 nA, 10 mmol/L) induced repetitive bursts in most cells tested (12/
