Immediate-early genes(IEGs) have long been used to visualize neural activations induced by sensory and behavioral stimuli. Recent advances in imaging techniques have made it possible to use endogenous IEG signals to v...Immediate-early genes(IEGs) have long been used to visualize neural activations induced by sensory and behavioral stimuli. Recent advances in imaging techniques have made it possible to use endogenous IEG signals to visualize and discriminate neural ensembles activated by multiple stimuli, and to map whole-brain-scale neural activation at single-neuron resolution. In addition, a collection of IEG-dependent molecular tools has been developed that can be used to complement the labeling of endogenous IEG genes and, especially, to manipulate activated neural ensembles in order to reveal the circuits and mechanisms underlying different behaviors. Here, we review these techniques and tools in terms of their utility in studying functional neural circuits. In addition, we provide an experimental strategy to measure the signal-to-noise ratio of IEG-dependent molecular tools, for evaluating their suitability for investigating relevant circuits and behaviors.展开更多
Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neurona...Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring.The structural reorganization of synaptic complexes,changes in actin cytos keleton and organelle dynamics,as well as modulation of gene expression,determine synaptic plasticity.It has been proposed that dys regulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases.Much is known about downstream signaling of activated N-methyl-D-aspartate andα-amino-3-hydroxy-5-methyl-4-isoazolepro pionate receptors;howeve r,other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory.The non-receptor tyrosine kinase c-Abl(ABL1)is a key signal transducer of intra and extracellular signals,and it shuttles between the cyto plasm and the nucleus.This review focuses on c-Abl and its synaptic and neuronal functions.Here,we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons,promoting the development of neurodegenerative diseases.Nevertheless,c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity,regulating dendritic spines remodeling and gene expression after cognitive training,and synaptic dysfunction and loss in neurodegenerative diseases.Thus,c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice,but its absence provides dendritic spines resiliency against damage.Therefo re,the present review has been designed to elu cidate the common links between c-Abl regulation of structural changes that involve the actin cytos keleton and organelles dynamics,and the transc riptional program activated during synaptic plasticity.By summarizing the recent discove ries on c-Abl functions,we aim to provide an overview of how its inhibition co uld be a potentially fruitful treatment to improve degenerative outcomes and delay memory loss.展开更多
Objective To construct a prokaryotic expression vector bearing fusion gene NT4-ADNF-9 for future studies on genetic therapies for sensorineural deafness. Methods Double strand ADNF-9 cDNA was synthesized using asymmet...Objective To construct a prokaryotic expression vector bearing fusion gene NT4-ADNF-9 for future studies on genetic therapies for sensorineural deafness. Methods Double strand ADNF-9 cDNA was synthesized using asymmetrical primer/ templates and ligated to the 3’ terminal of signal and leader peptides of neurotrophin 4 (NT4). The fusion gene NT4 -ADNF-9, was subcloned into prokaryotic expression vector pBV220, and named pBV220/ NT4-ADNF-9. DNA sequence of the fusion gene was analyzed. The fusion protein was isolated by SDS-PAGE and its bioactivity was evaluated using primary culture of day 8 chicken embryonic DRGcells. Results The correct sequence of fusion gene NT4-ADNF-9 was successfully subcloned into the pBV220 vector. The expressed ADNF-9 protein showed its effects in promoting cell survival and neurite growth. Conclusion Prokaryotic expression vector pBV220/NT4-ADNF-9 was constructed successfully and the expressed fusion protein demonstrated satisfactory bioactivity.展开更多
BACKGROUND： Epigenetic regulation is a level of transcriptional regulation that occurs in addition to the genetic programming found in biological systems. In the brain, the epigenetic machinery gives the system an op...BACKGROUND： Epigenetic regulation is a level of transcriptional regulation that occurs in addition to the genetic programming found in biological systems. In the brain, the epigenetic machinery gives the system an opportunity to adapt to a given environment to help not only the individual but also the species survive and expand. However, such a regulatory system has risks, as mutations resulting from epigenetic regulation can cause severe neurological or psychiatric disorders. OBJECTIVE： Here, we review the most recent findings regarding the epigenetic mechanisms that control the activity- dependent gene transcription leading to synaptic plasticity and brain function and the defects in these mechanisms that lead to neurological disorders. METHODS： A search was carded out systematically, searching all relevant publications up to June 2017, using the PubMed search engine. The following keywords were used： ＂activity induced epigenetic,＂ ＂gene transcription,＂ and ＂neurological disorders.＂ RESULTS： A wide range of studies focused on the roles of epigenetics in transgenerational inheritance, neural differentiation, neural circuit assembly and brain diseases. Thirty-one articles focused specifically on activity-induced epigenetic modifications that regulated gene transcription and memory formation and consolidation. CONCLUSION： Activity-dependent epigenetic mechanisms of gene expression regulation contribute to basic neuronal physiology, and defects were associated with an elevated risk for brain disorders.展开更多
基金supported by the National Natural Science Foundation of China(81571335,91432108 and81527901)grants from the Ministry of Science and Technology of China(2016YFA0501000)
文摘Immediate-early genes(IEGs) have long been used to visualize neural activations induced by sensory and behavioral stimuli. Recent advances in imaging techniques have made it possible to use endogenous IEG signals to visualize and discriminate neural ensembles activated by multiple stimuli, and to map whole-brain-scale neural activation at single-neuron resolution. In addition, a collection of IEG-dependent molecular tools has been developed that can be used to complement the labeling of endogenous IEG genes and, especially, to manipulate activated neural ensembles in order to reveal the circuits and mechanisms underlying different behaviors. Here, we review these techniques and tools in terms of their utility in studying functional neural circuits. In addition, we provide an experimental strategy to measure the signal-to-noise ratio of IEG-dependent molecular tools, for evaluating their suitability for investigating relevant circuits and behaviors.
基金supported by Comisión Nacional de Investigación Cientifica y Tecnologica-Chile Fondecyt 12011668(to ARA)Fondecyt 1190334(to SZ)+6 种基金Fondecyt 11200592(to MJY)Fondef ID21/10347(to ARA andSZ)Fondef D10E1077(to ARA and SZ)CARE-UCAFB 170005(to ARA)MSCA-RISE-2016-Lysomod-734825 European Union's Horizon 2020Research and Innovation Program under the Marie Sklodowska-Curie grant agreement N°953489(to SZ)Millennium Science Initiative Program-ICN09_016/ICN 2021_045(to ARA)。
文摘Our ability to learn and remember depends on the active formation,remodeling,and elimination of synapses.Thus,the development and growth of synapses as well as their weakening and elimination are essential for neuronal rewiring.The structural reorganization of synaptic complexes,changes in actin cytos keleton and organelle dynamics,as well as modulation of gene expression,determine synaptic plasticity.It has been proposed that dys regulation of these key synaptic homeostatic processes underlies the synaptic dysfunction observed in many neurodegenerative diseases.Much is known about downstream signaling of activated N-methyl-D-aspartate andα-amino-3-hydroxy-5-methyl-4-isoazolepro pionate receptors;howeve r,other signaling pathways can also contribute to synaptic plasticity and long-lasting changes in learning and memory.The non-receptor tyrosine kinase c-Abl(ABL1)is a key signal transducer of intra and extracellular signals,and it shuttles between the cyto plasm and the nucleus.This review focuses on c-Abl and its synaptic and neuronal functions.Here,we discuss the evidence showing that the activation of c-Abl can be detrimental to neurons,promoting the development of neurodegenerative diseases.Nevertheless,c-Abl activity seems to be in a pivotal balance between healthy synaptic plasticity,regulating dendritic spines remodeling and gene expression after cognitive training,and synaptic dysfunction and loss in neurodegenerative diseases.Thus,c-Abl genetic ablation not only improves learning and memory and modulates the brain genetic program of trained mice,but its absence provides dendritic spines resiliency against damage.Therefo re,the present review has been designed to elu cidate the common links between c-Abl regulation of structural changes that involve the actin cytos keleton and organelles dynamics,and the transc riptional program activated during synaptic plasticity.By summarizing the recent discove ries on c-Abl functions,we aim to provide an overview of how its inhibition co uld be a potentially fruitful treatment to improve degenerative outcomes and delay memory loss.
文摘Objective To construct a prokaryotic expression vector bearing fusion gene NT4-ADNF-9 for future studies on genetic therapies for sensorineural deafness. Methods Double strand ADNF-9 cDNA was synthesized using asymmetrical primer/ templates and ligated to the 3’ terminal of signal and leader peptides of neurotrophin 4 (NT4). The fusion gene NT4 -ADNF-9, was subcloned into prokaryotic expression vector pBV220, and named pBV220/ NT4-ADNF-9. DNA sequence of the fusion gene was analyzed. The fusion protein was isolated by SDS-PAGE and its bioactivity was evaluated using primary culture of day 8 chicken embryonic DRGcells. Results The correct sequence of fusion gene NT4-ADNF-9 was successfully subcloned into the pBV220 vector. The expressed ADNF-9 protein showed its effects in promoting cell survival and neurite growth. Conclusion Prokaryotic expression vector pBV220/NT4-ADNF-9 was constructed successfully and the expressed fusion protein demonstrated satisfactory bioactivity.
文摘BACKGROUND： Epigenetic regulation is a level of transcriptional regulation that occurs in addition to the genetic programming found in biological systems. In the brain, the epigenetic machinery gives the system an opportunity to adapt to a given environment to help not only the individual but also the species survive and expand. However, such a regulatory system has risks, as mutations resulting from epigenetic regulation can cause severe neurological or psychiatric disorders. OBJECTIVE： Here, we review the most recent findings regarding the epigenetic mechanisms that control the activity- dependent gene transcription leading to synaptic plasticity and brain function and the defects in these mechanisms that lead to neurological disorders. METHODS： A search was carded out systematically, searching all relevant publications up to June 2017, using the PubMed search engine. The following keywords were used： ＂activity induced epigenetic,＂ ＂gene transcription,＂ and ＂neurological disorders.＂ RESULTS： A wide range of studies focused on the roles of epigenetics in transgenerational inheritance, neural differentiation, neural circuit assembly and brain diseases. Thirty-one articles focused specifically on activity-induced epigenetic modifications that regulated gene transcription and memory formation and consolidation. CONCLUSION： Activity-dependent epigenetic mechanisms of gene expression regulation contribute to basic neuronal physiology, and defects were associated with an elevated risk for brain disorders.
