The structural plasticity of synaptic terminals contributes to normal nervous system function but also to neural degeneration, in the form of terminal retraction, and regeneration, due to process growth. Synaptic morp...The structural plasticity of synaptic terminals contributes to normal nervous system function but also to neural degeneration, in the form of terminal retraction, and regeneration, due to process growth. Synaptic morphological change is mediated through the actin cytoskeleton, which is enriched in axonal and dendritic terminals. Whereas the three RhoGTPases, RhoA, Cdc42 and Rac, function as upstream signaling nodes sensitive to extracellular stimuli, LIMK-cofilin activity serves as a common downstream effector to up-regulate actin turnover, which is necessary for both polymerization and depolymerization. The dual effects of LIMK activity make LIMK a potential target of therapeutic intervention for iniury-induced synaptic plasticity, as LIMK inhibition can stabilize actin cytoskeleton and preserve existing structure. This therapeutic benefit of LIMK inhibition has been demonstrated in animal models of injury-induced axon retraction and neuritic sprouting by rod photoreceptors. A better understanding of the regulation of LIMK-cofilin activity and the interaction with the microtubular cytoskeleton may open new ways to promote synaptic regeneration that can benefit neuronal degenerative disease.展开更多
Depression refers to a series of mental health issues characterized by loss of interest and enjoyment in everyday life,low mood and selected emotional,cognitive,physical and behavioral symptoms.Depression is a common ...Depression refers to a series of mental health issues characterized by loss of interest and enjoyment in everyday life,low mood and selected emotional,cognitive,physical and behavioral symptoms.Depression is a common disorder,affecting 5–15%of the general population.When diagnosed as major depressive disorder(MDD),patients are currentlytreated with pharmacological agents such as serotonin or noradren- aline uptake inhibitors (SSRI or SNRI) or tricyclics.展开更多
Visual deprivation leads to structural neuroplasticity in the blind subjects,including gray matter(GM)and white matter(WM)atrophy and alterations in structural connectivity.The rat model of binocular enucleation(BE)is...Visual deprivation leads to structural neuroplasticity in the blind subjects,including gray matter(GM)and white matter(WM)atrophy and alterations in structural connectivity.The rat model of binocular enucleation(BE)is a frequently used animal model for studying brain plasticity induced by early blindness.Yet few neuroimaging studies have been performed on this model to investigate whether or not the BE rats have image phenotypes similar to or comparable to,those observed in the early blind subjects.The current study aimed to assess brain structural plasticity in BE rats using anatomical magnetic resonance imaging(MRI)and diffusion tensor imaging(DTI).The results demonstrated that early BE at postnatal day 4(P4)caused almost complete degeneration of optic nerve(ON)and optic chiasma(OCH),atrophy in a number of visual and non-visual structures,including optic tract(OT),dorsal lateral geniculate nucleus(DLG)and corpus callosum(CC).The BE rats also exhibited impairments of WM microstructural integrity in the OT,and reduction of structural connectivity between the normal-appearing visual cortex(VC)and somatosensory/motor cortices at 4 months of age,likely as manifestations of deafferentationinduced maldevelopment.The structural neuroplasticity in BE rats observable to structural MRI parallels largely with what has been reported in blind subjects,suggesting that longitudinal neuroimaging studies on animal models of sensory deprivation can provide insights into how the brain changes its wiring and function during development/adaption in response to the lack of sensory stimuli.展开更多
Intermediate level of stress is beneficial for brain functions, whereas extreme low level or high level of stress is deleterious. We have previously shown that chronic exposure to high doses of corticosterone (CORT)...Intermediate level of stress is beneficial for brain functions, whereas extreme low level or high level of stress is deleterious. We have previously shown that chronic exposure to high doses of corticosterone (CORT) suppressed hippocampal plasticity and physical exercise in terms of running counteracted the detrimental effects of CORT treatment. We aimed to study whether a mild stress, that mimicked by a treatment with low CORT dose, improved hippocampal plasticity in terms of hippocampal cell proliferation and dendritic remodeling, and to examine whether running with CORT treatment showed an additive effect on improving hippocampal plasticity. The rats were treated with 20 mg/kg CORT for 14 days with or without running, followed by Morris water maze test or forced swim test. The hippocampal proliferating cells was labeled by intraperitoneal injection of 5-bromo-2'-deoxyuridine. The dendritic morphology was analyzed using Golgi staining method. Treatment with 20 mg/kg CORT alone yielded a higher number of hippocampal cell proliferation and significantly increased dendritic branching compared to vehicle-treated non-runners, but had no behavioral effects. In contrast, CORT treatment with running showed an additive increase in hippocampal cell proliferation and dendritic remodeling that was associated with improved spatial learning and decreased depression-like behavior; however, there was no additive improvement in behavior compared to vehicle-treated runners. These findings suggest that mild stress does not always cause detrimental effect on the brain, and combining mild stress with running could promote hippocampal plasticity via inducing cell proliferation and dendritic remodeling.展开更多
Continuous lifelong acquisition,updating,and finetuning of knowledge and skills is of crucial significance for the survival of humans.However,current neuromorphic devices exhibit obvious catastrophic forgetting when r...Continuous lifelong acquisition,updating,and finetuning of knowledge and skills is of crucial significance for the survival of humans.However,current neuromorphic devices exhibit obvious catastrophic forgetting when restimulated by new information.This remains a challenge for neuromorphic devices and artificial intelligence to achieve continuous learning.Herein,we propose an electric-induced cycloelimination strategy to realize an organic transistor nociceptor that can simulate synaptic and structural plasticity.The system benefits from the ring-opening characteristics of cross-linked poly(vinyl cinnamate)under a strong pulse voltage,during which new energy-level trap states are formed.The prepared organic transistor nociceptors exhibit both structural and synaptic plasticity.They simulate the characteristics of human nociceptors,including threshold,relaxation,sensitization,and maladaptation behavior.For the first time,we have simulated and explored the structural plasticity behavior in organisms based on electronic devices.More remarkably,the transistor nociceptors realize the reinput of information without forgetting the initial informa tion.The strategy developed for the preparation of organic transistor nociceptors provides insights for addressing the catastrophic forgetting in the lifelong learning of intelligent neuromorphic devices.展开更多
Autonomous one-shot on-the-fly learning copes with the high privacy,small dataset,and in-stream data at the edge.Implementing such learning on digital hardware suffers from the well-known von-Neumann and scaling bottl...Autonomous one-shot on-the-fly learning copes with the high privacy,small dataset,and in-stream data at the edge.Implementing such learning on digital hardware suffers from the well-known von-Neumann and scaling bottlenecks.The optical neural networks featuring large parallelism,low latency,and high efficiency offer a promising solution.However,ex-situ training of conventional optical networks,where optical path configuration and deep learning model optimization are separated,incurs hardware,energy and time overheads,and defeats the advantages in edge learning.Here,we introduced a bio-inspired material-algorithm co-design to construct a hydrogel-based optical Willshaw model(HOWM),manifesting Hebbian-rule-based structural plasticity for simultaneous optical path configuration and deep learning model optimization thanks to the underlying opto-chemical reactions.We first employed the HOWM as an all optical in-sensor AI processor for one-shot pattern classification,association and denoising.We then leveraged HOWM to function as a ternary content addressable memory(TCAM)of an optical memory augmented neural network(MANN)for one-shot learning the Omniglot dataset.The HOWM empowered one-shot on-the-fly edge learning leads to 1000boost of energy efficiency and 10boost of speed,which paves the way for the next-generation autonomous,efficient,and affordable smart edge systems.展开更多
As metallic foams used for energy absorption in the automotive and aerospace industries, recently invented lotus-type porous metals are viewed as potential energy absorbers. Yet, solid conclusion on their eligibility ...As metallic foams used for energy absorption in the automotive and aerospace industries, recently invented lotus-type porous metals are viewed as potential energy absorbers. Yet, solid conclusion on their eligibility as energy absorbers is still in question, particularly when compression is in the direction perpendicular to the axial orientation of cylindrical pores. In this work, the energy absorption of lotus-type porous coppers in the perpendicular direction is investigated at strain rates from 0.001 s^(-1) to^2400 s^(-1). The energy absorption capacity and the energy absorption efficiency are calculated to be4–16 k J/kg and 0.32–0.7, respectively, slightly inferior to metal foams and the same porous solid compressed in the parallel direction due to the shortened extent of the plateau stress region. The deformation mechanism is examined experimentally in conjunction with finite element modeling. Both suggest that gradual squeeze and collapse of pores are the mechanisms accommodating the energy absorption. The deformation is generally evenly distributed over pore ligaments and independent of strain rate.展开更多
The Chinese Materials Research Society(C-MRS)Conference(2015)was held in the Guizhou Park Hotel International Conference Center,Guiyang,China,from July 10-14,2015.This conference consists of 30symposia,including 4...The Chinese Materials Research Society(C-MRS)Conference(2015)was held in the Guizhou Park Hotel International Conference Center,Guiyang,China,from July 10-14,2015.This conference consists of 30symposia,including 4international symposia.As one of 4international symposia,"Serration and noise behavior in advanced materials"展开更多
基金supported by NIH grant EY021542 and the F.M.Kirby Foundation
文摘The structural plasticity of synaptic terminals contributes to normal nervous system function but also to neural degeneration, in the form of terminal retraction, and regeneration, due to process growth. Synaptic morphological change is mediated through the actin cytoskeleton, which is enriched in axonal and dendritic terminals. Whereas the three RhoGTPases, RhoA, Cdc42 and Rac, function as upstream signaling nodes sensitive to extracellular stimuli, LIMK-cofilin activity serves as a common downstream effector to up-regulate actin turnover, which is necessary for both polymerization and depolymerization. The dual effects of LIMK activity make LIMK a potential target of therapeutic intervention for iniury-induced synaptic plasticity, as LIMK inhibition can stabilize actin cytoskeleton and preserve existing structure. This therapeutic benefit of LIMK inhibition has been demonstrated in animal models of injury-induced axon retraction and neuritic sprouting by rod photoreceptors. A better understanding of the regulation of LIMK-cofilin activity and the interaction with the microtubular cytoskeleton may open new ways to promote synaptic regeneration that can benefit neuronal degenerative disease.
基金funded by Ministry of Education,University and Research(MIUR)ex-60% research fund University of Brescia,Italy
文摘Depression refers to a series of mental health issues characterized by loss of interest and enjoyment in everyday life,low mood and selected emotional,cognitive,physical and behavioral symptoms.Depression is a common disorder,affecting 5–15%of the general population.When diagnosed as major depressive disorder(MDD),patients are currentlytreated with pharmacological agents such as serotonin or noradren- aline uptake inhibitors (SSRI or SNRI) or tricyclics.
基金the the National Natural Science Foundation of China(Nos.81000598).
文摘Visual deprivation leads to structural neuroplasticity in the blind subjects,including gray matter(GM)and white matter(WM)atrophy and alterations in structural connectivity.The rat model of binocular enucleation(BE)is a frequently used animal model for studying brain plasticity induced by early blindness.Yet few neuroimaging studies have been performed on this model to investigate whether or not the BE rats have image phenotypes similar to or comparable to,those observed in the early blind subjects.The current study aimed to assess brain structural plasticity in BE rats using anatomical magnetic resonance imaging(MRI)and diffusion tensor imaging(DTI).The results demonstrated that early BE at postnatal day 4(P4)caused almost complete degeneration of optic nerve(ON)and optic chiasma(OCH),atrophy in a number of visual and non-visual structures,including optic tract(OT),dorsal lateral geniculate nucleus(DLG)and corpus callosum(CC).The BE rats also exhibited impairments of WM microstructural integrity in the OT,and reduction of structural connectivity between the normal-appearing visual cortex(VC)and somatosensory/motor cortices at 4 months of age,likely as manifestations of deafferentationinduced maldevelopment.The structural neuroplasticity in BE rats observable to structural MRI parallels largely with what has been reported in blind subjects,suggesting that longitudinal neuroimaging studies on animal models of sensory deprivation can provide insights into how the brain changes its wiring and function during development/adaption in response to the lack of sensory stimuli.
基金Jessie Ho Professorship in Neuroscience (The University of Hong Kong Foundation for Educational Development and Research Limited)the National Natural Science Foundation of China+1 种基金the Areas of Excellence (AoE) Scheme Established under the University Grants Committee of the Hong Kong and AoE Matching Fund from the University of Hong Kong, No. 21609101the Fundamental Research Funds for the Central Universities, No. 09ykpy25, 09ykpy31
文摘Intermediate level of stress is beneficial for brain functions, whereas extreme low level or high level of stress is deleterious. We have previously shown that chronic exposure to high doses of corticosterone (CORT) suppressed hippocampal plasticity and physical exercise in terms of running counteracted the detrimental effects of CORT treatment. We aimed to study whether a mild stress, that mimicked by a treatment with low CORT dose, improved hippocampal plasticity in terms of hippocampal cell proliferation and dendritic remodeling, and to examine whether running with CORT treatment showed an additive effect on improving hippocampal plasticity. The rats were treated with 20 mg/kg CORT for 14 days with or without running, followed by Morris water maze test or forced swim test. The hippocampal proliferating cells was labeled by intraperitoneal injection of 5-bromo-2'-deoxyuridine. The dendritic morphology was analyzed using Golgi staining method. Treatment with 20 mg/kg CORT alone yielded a higher number of hippocampal cell proliferation and significantly increased dendritic branching compared to vehicle-treated non-runners, but had no behavioral effects. In contrast, CORT treatment with running showed an additive increase in hippocampal cell proliferation and dendritic remodeling that was associated with improved spatial learning and decreased depression-like behavior; however, there was no additive improvement in behavior compared to vehicle-treated runners. These findings suggest that mild stress does not always cause detrimental effect on the brain, and combining mild stress with running could promote hippocampal plasticity via inducing cell proliferation and dendritic remodeling.
基金the National Key R&D Program(grant no.2018YFA0703200)the National Natural Science Foundation of China(grant nos.61890940 and 52003274)+3 种基金the Chinese Academy of Sciences(CAS)Project for Young Scientists in Basic Research(grant no.YSBR-053)the Strategic Priority Research Program of the CAS(grant no.XDB30000000)the CAS-Croucher Funding Scheme for Joint Laboratories,the CAS Cooperation Projects(grant no.121111KYSB20200036)Lu Jiaxi international team(grant no.GJTD-2020-02).
文摘Continuous lifelong acquisition,updating,and finetuning of knowledge and skills is of crucial significance for the survival of humans.However,current neuromorphic devices exhibit obvious catastrophic forgetting when restimulated by new information.This remains a challenge for neuromorphic devices and artificial intelligence to achieve continuous learning.Herein,we propose an electric-induced cycloelimination strategy to realize an organic transistor nociceptor that can simulate synaptic and structural plasticity.The system benefits from the ring-opening characteristics of cross-linked poly(vinyl cinnamate)under a strong pulse voltage,during which new energy-level trap states are formed.The prepared organic transistor nociceptors exhibit both structural and synaptic plasticity.They simulate the characteristics of human nociceptors,including threshold,relaxation,sensitization,and maladaptation behavior.For the first time,we have simulated and explored the structural plasticity behavior in organisms based on electronic devices.More remarkably,the transistor nociceptors realize the reinput of information without forgetting the initial informa tion.The strategy developed for the preparation of organic transistor nociceptors provides insights for addressing the catastrophic forgetting in the lifelong learning of intelligent neuromorphic devices.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0701500)Hong Kong Research Grant Council(Grant No.27206321,17205922)+5 种基金the National Natural Science Foundation of China(Grant Nos.62122004,61874138,61888102,61771176,and 62171173)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB44000000)Research on the GaN Chip for 5G Applications(Grant No:JCYJ20210324120409025)Research on high-reliable GaN power device and the related industrial power system(Grant No:HZQBKCZYZ-2021052)Key Project of Department of Education of Guangdong Province(No.2018KCXTD026)supported by ACCESS-AI Chip Center for Emerging Smart Systems,sponsored by Innovation and Technology Fund(ITF),Hong Kong SAR.
文摘Autonomous one-shot on-the-fly learning copes with the high privacy,small dataset,and in-stream data at the edge.Implementing such learning on digital hardware suffers from the well-known von-Neumann and scaling bottlenecks.The optical neural networks featuring large parallelism,low latency,and high efficiency offer a promising solution.However,ex-situ training of conventional optical networks,where optical path configuration and deep learning model optimization are separated,incurs hardware,energy and time overheads,and defeats the advantages in edge learning.Here,we introduced a bio-inspired material-algorithm co-design to construct a hydrogel-based optical Willshaw model(HOWM),manifesting Hebbian-rule-based structural plasticity for simultaneous optical path configuration and deep learning model optimization thanks to the underlying opto-chemical reactions.We first employed the HOWM as an all optical in-sensor AI processor for one-shot pattern classification,association and denoising.We then leveraged HOWM to function as a ternary content addressable memory(TCAM)of an optical memory augmented neural network(MANN)for one-shot learning the Omniglot dataset.The HOWM empowered one-shot on-the-fly edge learning leads to 1000boost of energy efficiency and 10boost of speed,which paves the way for the next-generation autonomous,efficient,and affordable smart edge systems.
基金financial support from the National Natural Science Foundation of China (Grant No. 50904004)
文摘As metallic foams used for energy absorption in the automotive and aerospace industries, recently invented lotus-type porous metals are viewed as potential energy absorbers. Yet, solid conclusion on their eligibility as energy absorbers is still in question, particularly when compression is in the direction perpendicular to the axial orientation of cylindrical pores. In this work, the energy absorption of lotus-type porous coppers in the perpendicular direction is investigated at strain rates from 0.001 s^(-1) to^2400 s^(-1). The energy absorption capacity and the energy absorption efficiency are calculated to be4–16 k J/kg and 0.32–0.7, respectively, slightly inferior to metal foams and the same porous solid compressed in the parallel direction due to the shortened extent of the plateau stress region. The deformation mechanism is examined experimentally in conjunction with finite element modeling. Both suggest that gradual squeeze and collapse of pores are the mechanisms accommodating the energy absorption. The deformation is generally evenly distributed over pore ligaments and independent of strain rate.
文摘The Chinese Materials Research Society(C-MRS)Conference(2015)was held in the Guizhou Park Hotel International Conference Center,Guiyang,China,from July 10-14,2015.This conference consists of 30symposia,including 4international symposia.As one of 4international symposia,"Serration and noise behavior in advanced materials"