Planarian is among the simplest animals that possess a centralized nervous system （CNS）, and its neural regenera- tion involves the replacement of cells lost to normal ＇wear and tear＇ （cell turnover）, and/or inj...Planarian is among the simplest animals that possess a centralized nervous system （CNS）, and its neural regenera- tion involves the replacement of cells lost to normal ＇wear and tear＇ （cell turnover）, and/or injury. In this review, we state and discuss the recent studies on molecular control of neural regeneration in planarians. The spatial and temporal expression patterns of genes in intact and regenerating planarian CNS have already been described relatively clearly. The bone morphogenetic protein （BMP） and Wnt signaling pathways are identified to regulate neural regeneration. During neural regeneration, conserved axon guidance mechanisms are necessary for proper wiring of the nervous system. In addition, apoptosis may play an important role in controlling cell numbers, eliminating unnecessary tissues or cells and remodeling the old tissues for regenerating CNS. The bilateral symmetry is established by determination of anterior-posterior （A-P） and dorsal-ventral （D-V） patterns. Moreover, neurons positive to dopamine, serotonin （5-HT）, and gamma-aminobutyric acid （GABA） have been detected in planarians. Therefore, planarians present us with new, experimentally accessible contexts to study the molecular actions guiding neural regeneration.展开更多
Neurodegenerative diseases are characterized by the accumulation of intracellular or extracellular protein aggregates that result from conformational changes in proteins. These diseases may result from an imbalance be...Neurodegenerative diseases are characterized by the accumulation of intracellular or extracellular protein aggregates that result from conformational changes in proteins. These diseases may result from an imbalance between the produetion of misfolded proteins and normal chaperone capacity. Molecular chaperones provide a first line of defenee against misfolded, aggragation-prone proteins and are, therefore, promising therapeutic targets for neurodegenerative diseases.展开更多
Model invertebrate organism Caenorhabditis elegans has become an ideal model to unravel the complex processes of memory. C. elegans has three simple forms of memory： memory for thermosensation, memory for chemosensat...Model invertebrate organism Caenorhabditis elegans has become an ideal model to unravel the complex processes of memory. C. elegans has three simple forms of memory： memory for thermosensation, memory for chemosensation, and memory for mechanosensation. In the form of memory for mechanosensation, short-term memory, intermediate-term memory, and long-term memory have been extensively studied. The short-term memory and intermediate-term memory may occur in the presynaptic sensory neurons, whereas the long-term memory may occur in the postsynaptic interneurons. This review will discuss the recent progress on genetic and molecular regulation of memory in C. elegans.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
The limited regenerative capacity of several organs, such as central nervous system(CNS), heart and limb in mammals makes related major diseases quite difficult to recover. Therefore, dissection of the cellular and mo...The limited regenerative capacity of several organs, such as central nervous system(CNS), heart and limb in mammals makes related major diseases quite difficult to recover. Therefore, dissection of the cellular and molecular mechanisms underlying organ regeneration is of great scientific and clinical interests. Tremendous progression has already been made after extensive investigations using several model organisms for decades. Unfortunately, distance to the final achievement of the goal still remains. Recently, zebrafish became a popular model organism for the deep understanding of regeneration based on its powerful regenerative capacity, in particular the organs that are limitedly regenerated in mammals. Additionally, zebrafish are endowed with other advantages good for the study of organ regeneration. This review summarizes the recent progress in the study of zebrafish organ regeneration, in particular regeneration of fin, heart, CNS, and liver as the representatives. We also discuss reasons of the reduced regenerative capacity in higher vertebrate, the roles of inflammation during regeneration, and the difference between organogenesis and regeneration.展开更多
基金the Southeast University Foundation for Excellent Young Scholars (No. 4023001013)the Program for New Century Excellent Talents in University.
文摘Planarian is among the simplest animals that possess a centralized nervous system （CNS）, and its neural regenera- tion involves the replacement of cells lost to normal ＇wear and tear＇ （cell turnover）, and/or injury. In this review, we state and discuss the recent studies on molecular control of neural regeneration in planarians. The spatial and temporal expression patterns of genes in intact and regenerating planarian CNS have already been described relatively clearly. The bone morphogenetic protein （BMP） and Wnt signaling pathways are identified to regulate neural regeneration. During neural regeneration, conserved axon guidance mechanisms are necessary for proper wiring of the nervous system. In addition, apoptosis may play an important role in controlling cell numbers, eliminating unnecessary tissues or cells and remodeling the old tissues for regenerating CNS. The bilateral symmetry is established by determination of anterior-posterior （A-P） and dorsal-ventral （D-V） patterns. Moreover, neurons positive to dopamine, serotonin （5-HT）, and gamma-aminobutyric acid （GABA） have been detected in planarians. Therefore, planarians present us with new, experimentally accessible contexts to study the molecular actions guiding neural regeneration.
文摘Neurodegenerative diseases are characterized by the accumulation of intracellular or extracellular protein aggregates that result from conformational changes in proteins. These diseases may result from an imbalance between the produetion of misfolded proteins and normal chaperone capacity. Molecular chaperones provide a first line of defenee against misfolded, aggragation-prone proteins and are, therefore, promising therapeutic targets for neurodegenerative diseases.
文摘Model invertebrate organism Caenorhabditis elegans has become an ideal model to unravel the complex processes of memory. C. elegans has three simple forms of memory： memory for thermosensation, memory for chemosensation, and memory for mechanosensation. In the form of memory for mechanosensation, short-term memory, intermediate-term memory, and long-term memory have been extensively studied. The short-term memory and intermediate-term memory may occur in the presynaptic sensory neurons, whereas the long-term memory may occur in the postsynaptic interneurons. This review will discuss the recent progress on genetic and molecular regulation of memory in C. elegans.
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The limited regenerative capacity of several organs, such as central nervous system(CNS), heart and limb in mammals makes related major diseases quite difficult to recover. Therefore, dissection of the cellular and molecular mechanisms underlying organ regeneration is of great scientific and clinical interests. Tremendous progression has already been made after extensive investigations using several model organisms for decades. Unfortunately, distance to the final achievement of the goal still remains. Recently, zebrafish became a popular model organism for the deep understanding of regeneration based on its powerful regenerative capacity, in particular the organs that are limitedly regenerated in mammals. Additionally, zebrafish are endowed with other advantages good for the study of organ regeneration. This review summarizes the recent progress in the study of zebrafish organ regeneration, in particular regeneration of fin, heart, CNS, and liver as the representatives. We also discuss reasons of the reduced regenerative capacity in higher vertebrate, the roles of inflammation during regeneration, and the difference between organogenesis and regeneration.
