小世界神经网络具有较快的收敛速度和优越的容错性,近年来得到广泛关注.然而,在网络构造过程中,随机重连可能造成重要信息丢失,进而导致网络精度下降.针对该问题,基于Watts-Strogatz(WS)型小世界神经网络,提出了一种基于突触巩固机制的...小世界神经网络具有较快的收敛速度和优越的容错性,近年来得到广泛关注.然而,在网络构造过程中,随机重连可能造成重要信息丢失,进而导致网络精度下降.针对该问题,基于Watts-Strogatz(WS)型小世界神经网络,提出了一种基于突触巩固机制的前馈小世界神经网络(Feedforward small-world neural network based on synaptic consolidation,FSWNN-SC).首先,使用网络正则化方法对规则前馈神经网络进行预训练,基于突触巩固机制,断开网络不重要的权值连接,保留重要的连接权值;其次,设计重连规则构造小世界神经网络,在保证网络小世界属性的同时实现网络稀疏化,并使用梯度下降算法训练网络;最后,通过4个UCI基准数据集和2个真实数据集进行模型性能测试,并使用Wilcoxon符号秩检验对对比模型进行显著性差异检验.实验结果表明:所提出的FSWNN-SC模型在获得紧凑的网络结构的同时,其精度显著优于规则前馈神经网络及其他WS型小世界神经网络.展开更多
大量研究表明,神经元的突触可塑性包括功能可塑性和结构可塑性,与学习和记忆密切相关.最近,在经过训练的动物海马区,记录到了学习诱导的长时程增强(long term potentiation,LTP),如果用激酶抑制剂阻断晚期LTP,就会使大鼠丧失训练形成的...大量研究表明,神经元的突触可塑性包括功能可塑性和结构可塑性,与学习和记忆密切相关.最近,在经过训练的动物海马区,记录到了学习诱导的长时程增强(long term potentiation,LTP),如果用激酶抑制剂阻断晚期LTP,就会使大鼠丧失训练形成的记忆.这些结果指出,LTP可能是形成记忆的分子基础.因此,进一步研究哺乳动物脑内突触可塑性的分子机制,对揭示学习和记忆的神经基础有重要意义.此外,在精神迟滞性疾病和神经退行性疾病患者脑内记录到异常的LTP,并发现神经元的树突棘数量减少,形态上产生畸变或萎缩,同时发现,产生突变的基因大多编码调节突触可塑性的信号通路蛋白,故突触可塑性研究也将促进精神和神经疾病的预防和治疗.综述了突触可塑性研究的最新进展,并展望了其发展前景.展开更多
Since Caenorhabditis elegans was chosen as a model organism by Sydney Brenner in 1960's, genetic studies in this organism have been instrumental in discovering the function of genes and in deciphering molecular si...Since Caenorhabditis elegans was chosen as a model organism by Sydney Brenner in 1960's, genetic studies in this organism have been instrumental in discovering the function of genes and in deciphering molecular signaling network. The small size of the organism and the simple nervous system enable the complete reconstruction of the first connectome. The stereotypic developmental program and the anatomical reproducibility of synaptic connections provide a blueprint to dissect the mechanisms underlying synapse formation. Recent technological innovation using laser surgery of single axons and in vivo imaging has also made C. elegans a new model for axon regeneration. Importantly, genes regulating synaptogenesis and axon regeneration are highly conserved in function across animal phyla. This mini-review will summarize the main approaches and the key findings in understanding the mechanisms underlying the development and maintenance of the nervous system. The impact of such findings underscores the awesome power of C. elegans genetics.展开更多
Neurotransmitter-containing synaptic vesicle(SV)fusion with the nerve terminal plasma membrane initiates neurotransmission in response to neuronal excitation.Under mild stimulation,the fused vesicular membrane is retr...Neurotransmitter-containing synaptic vesicle(SV)fusion with the nerve terminal plasma membrane initiates neurotransmission in response to neuronal excitation.Under mild stimulation,the fused vesicular membrane is retrieved via kiss-and-run and/or clathrin-mediated endocytosis,which is sufficient to maintain recycling of SVs.When neurons are challenged with very high stimulation,the number of fused SVs can be extremely high,resulting in significant plasma membrane addition.Under such conditions,a higher capacity retrieval pathway,bulk endocytosis,is activated to redress this large membrane imbalance.Despite first being described more than 40 years ago,the molecular mechanisms underpinning this important process have yet to be clearly defined.In this review,we highlight the current evidence for bulk endocytosis and its prevalence in various neuronal models,as well as discuss the underlying molecular components.展开更多
Erratum to:SCIENCE CHINA Life Sciences,November 2015 Vol.58 No.11:1084–1088doi:10.1007/s11427-015-4962-9In the first paragraph of the manuscript,the name of Charles Harrington was printed in error,should be Charles S...Erratum to:SCIENCE CHINA Life Sciences,November 2015 Vol.58 No.11:1084–1088doi:10.1007/s11427-015-4962-9In the first paragraph of the manuscript,the name of Charles Harrington was printed in error,should be Charles Sherrington.展开更多
文摘小世界神经网络具有较快的收敛速度和优越的容错性,近年来得到广泛关注.然而,在网络构造过程中,随机重连可能造成重要信息丢失,进而导致网络精度下降.针对该问题,基于Watts-Strogatz(WS)型小世界神经网络,提出了一种基于突触巩固机制的前馈小世界神经网络(Feedforward small-world neural network based on synaptic consolidation,FSWNN-SC).首先,使用网络正则化方法对规则前馈神经网络进行预训练,基于突触巩固机制,断开网络不重要的权值连接,保留重要的连接权值;其次,设计重连规则构造小世界神经网络,在保证网络小世界属性的同时实现网络稀疏化,并使用梯度下降算法训练网络;最后,通过4个UCI基准数据集和2个真实数据集进行模型性能测试,并使用Wilcoxon符号秩检验对对比模型进行显著性差异检验.实验结果表明:所提出的FSWNN-SC模型在获得紧凑的网络结构的同时,其精度显著优于规则前馈神经网络及其他WS型小世界神经网络.
文摘大量研究表明,神经元的突触可塑性包括功能可塑性和结构可塑性,与学习和记忆密切相关.最近,在经过训练的动物海马区,记录到了学习诱导的长时程增强(long term potentiation,LTP),如果用激酶抑制剂阻断晚期LTP,就会使大鼠丧失训练形成的记忆.这些结果指出,LTP可能是形成记忆的分子基础.因此,进一步研究哺乳动物脑内突触可塑性的分子机制,对揭示学习和记忆的神经基础有重要意义.此外,在精神迟滞性疾病和神经退行性疾病患者脑内记录到异常的LTP,并发现神经元的树突棘数量减少,形态上产生畸变或萎缩,同时发现,产生突变的基因大多编码调节突触可塑性的信号通路蛋白,故突触可塑性研究也将促进精神和神经疾病的预防和治疗.综述了突触可塑性研究的最新进展,并展望了其发展前景.
基金support from the National Institute of Healththe Howard Hughes Medical Institute of the United States of America
文摘Since Caenorhabditis elegans was chosen as a model organism by Sydney Brenner in 1960's, genetic studies in this organism have been instrumental in discovering the function of genes and in deciphering molecular signaling network. The small size of the organism and the simple nervous system enable the complete reconstruction of the first connectome. The stereotypic developmental program and the anatomical reproducibility of synaptic connections provide a blueprint to dissect the mechanisms underlying synapse formation. Recent technological innovation using laser surgery of single axons and in vivo imaging has also made C. elegans a new model for axon regeneration. Importantly, genes regulating synaptogenesis and axon regeneration are highly conserved in function across animal phyla. This mini-review will summarize the main approaches and the key findings in understanding the mechanisms underlying the development and maintenance of the nervous system. The impact of such findings underscores the awesome power of C. elegans genetics.
文摘Neurotransmitter-containing synaptic vesicle(SV)fusion with the nerve terminal plasma membrane initiates neurotransmission in response to neuronal excitation.Under mild stimulation,the fused vesicular membrane is retrieved via kiss-and-run and/or clathrin-mediated endocytosis,which is sufficient to maintain recycling of SVs.When neurons are challenged with very high stimulation,the number of fused SVs can be extremely high,resulting in significant plasma membrane addition.Under such conditions,a higher capacity retrieval pathway,bulk endocytosis,is activated to redress this large membrane imbalance.Despite first being described more than 40 years ago,the molecular mechanisms underpinning this important process have yet to be clearly defined.In this review,we highlight the current evidence for bulk endocytosis and its prevalence in various neuronal models,as well as discuss the underlying molecular components.
文摘Erratum to:SCIENCE CHINA Life Sciences,November 2015 Vol.58 No.11:1084–1088doi:10.1007/s11427-015-4962-9In the first paragraph of the manuscript,the name of Charles Harrington was printed in error,should be Charles Sherrington.
