The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Yuji Ikegaya - One of the best experts on this subject based on the ideXlab platform.
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Dynamic synapses as archives of Synaptic history: state‐dependent redistribution of Synaptic Efficacy in the rat hippocampal CA1
The Journal of Physiology, 2005Co-Authors: Takuya Yasui, Shigeyoshi Fujisawa, Masako Tsukamoto, Norio Matsuki, Yuji IkegayaAbstract:Plastic modifications of Synaptic strength are putative mechanisms underlying information processing in the brain, including memory storage, signal integration and filtering. Here we describe a dynamic interplay between short-term and long-term Synaptic plasticity. At rat hippocampal CA1 synapses, induction of both long-term potentiation (LTP) and depression (LTD) was accompanied by changes in the profile of short-term plasticity, termed redistribution of Synaptic Efficacy (RSE). RSE was preSynaptically expressed and associated in part with a persistent alteration in hyperpolarization-activated Ih channel activity. Already potentiated synapses were still capable of showing RSE in response to additional LTP-triggering stimulation. Strikingly, RSE took place even after reversal of LTP or LTD, that is, the same synapse can display different levels of short-term plasticity without changing Synaptic Efficacy for the initial spike in burst preSynaptic firing, thereby modulating spike transmission in a firing rate-dependent manner. Thus, the history of long-term Synaptic plasticity is registered in the form of short-term plasticity, and RSE extends the information storage capacity of a synapse and adds another dimension of functional complexity to neuronal operations.
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Dynamic synapses as archives of Synaptic history: state-dependent redistribution of Synaptic Efficacy in the rat hippocampal CA1.
The Journal of physiology, 2005Co-Authors: Takuya Yasui, Shigeyoshi Fujisawa, Masako Tsukamoto, Norio Matsuki, Yuji IkegayaAbstract:Plastic modifications of Synaptic strength are putative mechanisms underlying information processing in the brain, including memory storage, signal integration and filtering. Here we describe a dynamic interplay between short-term and long-term Synaptic plasticity. At rat hippocampal CA1 synapses, induction of both long-term potentiation (LTP) and depression (LTD) was accompanied by changes in the profile of short-term plasticity, termed redistribution of Synaptic Efficacy (RSE). RSE was preSynaptically expressed and associated in part with a persistent alteration in hyperpolarization-activated I(h) channel activity. Already potentiated synapses were still capable of showing RSE in response to additional LTP-triggering stimulation. Strikingly, RSE took place even after reversal of LTP or LTD, that is, the same synapse can display different levels of short-term plasticity without changing Synaptic Efficacy for the initial spike in burst preSynaptic firing, thereby modulating spike transmission in a firing rate-dependent manner. Thus, the history of long-term Synaptic plasticity is registered in the form of short-term plasticity, and RSE extends the information storage capacity of a synapse and adds another dimension of functional complexity to neuronal operations.
Takuya Yasui - One of the best experts on this subject based on the ideXlab platform.
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Dynamic synapses as archives of Synaptic history: state‐dependent redistribution of Synaptic Efficacy in the rat hippocampal CA1
The Journal of Physiology, 2005Co-Authors: Takuya Yasui, Shigeyoshi Fujisawa, Masako Tsukamoto, Norio Matsuki, Yuji IkegayaAbstract:Plastic modifications of Synaptic strength are putative mechanisms underlying information processing in the brain, including memory storage, signal integration and filtering. Here we describe a dynamic interplay between short-term and long-term Synaptic plasticity. At rat hippocampal CA1 synapses, induction of both long-term potentiation (LTP) and depression (LTD) was accompanied by changes in the profile of short-term plasticity, termed redistribution of Synaptic Efficacy (RSE). RSE was preSynaptically expressed and associated in part with a persistent alteration in hyperpolarization-activated Ih channel activity. Already potentiated synapses were still capable of showing RSE in response to additional LTP-triggering stimulation. Strikingly, RSE took place even after reversal of LTP or LTD, that is, the same synapse can display different levels of short-term plasticity without changing Synaptic Efficacy for the initial spike in burst preSynaptic firing, thereby modulating spike transmission in a firing rate-dependent manner. Thus, the history of long-term Synaptic plasticity is registered in the form of short-term plasticity, and RSE extends the information storage capacity of a synapse and adds another dimension of functional complexity to neuronal operations.
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Dynamic synapses as archives of Synaptic history: state-dependent redistribution of Synaptic Efficacy in the rat hippocampal CA1.
The Journal of physiology, 2005Co-Authors: Takuya Yasui, Shigeyoshi Fujisawa, Masako Tsukamoto, Norio Matsuki, Yuji IkegayaAbstract:Plastic modifications of Synaptic strength are putative mechanisms underlying information processing in the brain, including memory storage, signal integration and filtering. Here we describe a dynamic interplay between short-term and long-term Synaptic plasticity. At rat hippocampal CA1 synapses, induction of both long-term potentiation (LTP) and depression (LTD) was accompanied by changes in the profile of short-term plasticity, termed redistribution of Synaptic Efficacy (RSE). RSE was preSynaptically expressed and associated in part with a persistent alteration in hyperpolarization-activated I(h) channel activity. Already potentiated synapses were still capable of showing RSE in response to additional LTP-triggering stimulation. Strikingly, RSE took place even after reversal of LTP or LTD, that is, the same synapse can display different levels of short-term plasticity without changing Synaptic Efficacy for the initial spike in burst preSynaptic firing, thereby modulating spike transmission in a firing rate-dependent manner. Thus, the history of long-term Synaptic plasticity is registered in the form of short-term plasticity, and RSE extends the information storage capacity of a synapse and adds another dimension of functional complexity to neuronal operations.
Corey S. Goodman - One of the best experts on this subject based on the ideXlab platform.
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Synapse-specific control of Synaptic Efficacy at the terminals of a single neuron
Nature, 1998Co-Authors: Graeme W. Davis, Corey S. GoodmanAbstract:The regulation of Synaptic Efficacy is essential for the proper functioning of neural circuits. If Synaptic gain is set too high or too low, cells are either activated inappropriately or remain silent. There is extra complexity because synapses are not static, but form, retract, expand, strengthen, and weaken throughout life. Homeostatic regulatory mechanisms that control Synaptic Efficacy presumably exist to ensure that neurons remain functional within a meaningful physiological range1,2,3,4,5. One of the best defined systems for analysis of the mechanisms that regulate Synaptic Efficacy is the neuromuscular junction. It has been shown, in organisms ranging from insects to humans, that changes in Synaptic Efficacy are tightly coupled to changes in muscle size during development1,6,7,8. It has been proposed that a signal from muscle to motor neuron maintains this coupling9. Here we show, by genetically manipulating muscle innervation, that there are two independent mechanisms by which muscle regulates Synaptic Efficacy at the terminals of single motor neurons. Increased muscle innervation results in a compensatory, target-specific decrease in preSynaptic transmitter release, implying a retrograde regulation of preSynaptic release. Decreased muscle innervation results in a compensatory increase in quantal size.
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Genetic analysis of Synaptic development and plasticity: homeostatic regulation of Synaptic Efficacy.
Current opinion in neurobiology, 1998Co-Authors: Graeme W. Davis, Corey S. GoodmanAbstract:When experimentally challenged with perturbations in Synaptic structure and function, neurons have the remarkable ability to regulate their Synaptic Efficacy back to the normal range. Recent genetic analysis has provided insights into the mechanisms controlling this form of Synaptic homeostasis, with implications for our understanding of Synaptic development and plasticity.
Francis Crepel - One of the best experts on this subject based on the ideXlab platform.
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Synapses between parallel fibres and stellate cells express long-term changes in Synaptic Efficacy in rat cerebellum.
The Journal of Physiology, 2004Co-Authors: Armelle Rancillac, Francis CrepelAbstract:Various forms of Synaptic plasticity underlying motor learning have already been well characterized at cerebellar parallel fibre (PF)–Purkinje cell (PC) synapses. Inhibitory interneurones play an important role in controlling the excitability and synchronization of PCs. We have therefore tested the possibility that excitatory synapses between PFs and stellate cells (SCs) are also able to exhibit long-term changes in Synaptic Efficacy. In the present study, we show that long-term potentiation (LTP) and long-term depression (LTD) were induced at these synapses by a low frequency stimulation protocol (2 Hz for 60 s) and that pairing this low frequency stimulation protocol with postSynaptic depolarization induced a marked shift of Synaptic plasticity in favour of LTP. This LTP was cAMP independent, but required nitric oxide (NO) production from pre- and/or postSynaptic elements, depending on the stimulation or pairing protocol used, respectively. In contrast, LTD was not dependent on NO production but it required activation of postSynaptic group II and possibly of group I metabotropic glutamate receptors. Finally, stimulation of PFs at 8 Hz for 15 s also induced LTP at PF–SC synapses. But in this case, LTP was cAMP dependent, as was also observed at PF–PC synapses for preSynaptic LTP induced in the same conditions. Thus, long-term changes in Synaptic Efficacy can be accomplished by PF–SCs synapses as well as by PF–PC synapses, suggesting that both types of plasticity might co-operate during cerebellar motor learning.
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Blockade of NMDA receptors unmasks a long-term depression in Synaptic Efficacy in rat prefrontal neurons in vitro.
Experimental brain research, 1991Co-Authors: J C Hirsch, Francis CrepelAbstract:All the experiments were carried out in slices of rat prefrontal cortex maintained in vitro. The effect of 2-amino-5-phosphonovalerate (APV) was tested on the postSynaptic potential (PSP) recorded in layer V pyramidal cells, in response to single or high frequency stimulation of the superficial layers I–II. Wash-out of Mg2+ increased the amplitude and duration of the PSPs. This effect resulted from activation of N-methyl-D-aspartate (NMDA) receptors since it was suppressed by bath application of APV. Furthermore, in every cell tested in Mg2+ containing medium (N=16), exposure to APV reversibly reduced both mono- and polySynaptic components of the PSPs, indicating that, even in the control solution, activation of NMDA-coupled channels contributed to these Synaptic events. Finally, the anomalous voltage-dependence of the EPSP in the presence of Mg2+ and its sensitivity to APV suggests that at least a fraction of the NMDA receptors are postSynaptically located. Tetanization was applied to the afferents of cells bathed in control- or APV-medium. Long-term potentiation (LTP) or long-term depression (LTD) is defined as an increase or a decrease respectively, of the PSPs peak amplitude or initial slope, lasting 20 min. In the control medium, LTP in Synaptic Efficacy was observed in 34% of the cells and LTD in 48% (N=23). When exposed to APV, none of the cells tested (N=16) showed LTP of the response. In contrast, the tetanus induced a LTD of the PSP amplitude or slope in 14 out of these 16 cells. The percentage of cells showing LTD in Synaptic Efficacy (87%) when the NMDA receptors activation was blocked was significantly higher than that in control-medium.
Masako Tsukamoto - One of the best experts on this subject based on the ideXlab platform.
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Dynamic synapses as archives of Synaptic history: state‐dependent redistribution of Synaptic Efficacy in the rat hippocampal CA1
The Journal of Physiology, 2005Co-Authors: Takuya Yasui, Shigeyoshi Fujisawa, Masako Tsukamoto, Norio Matsuki, Yuji IkegayaAbstract:Plastic modifications of Synaptic strength are putative mechanisms underlying information processing in the brain, including memory storage, signal integration and filtering. Here we describe a dynamic interplay between short-term and long-term Synaptic plasticity. At rat hippocampal CA1 synapses, induction of both long-term potentiation (LTP) and depression (LTD) was accompanied by changes in the profile of short-term plasticity, termed redistribution of Synaptic Efficacy (RSE). RSE was preSynaptically expressed and associated in part with a persistent alteration in hyperpolarization-activated Ih channel activity. Already potentiated synapses were still capable of showing RSE in response to additional LTP-triggering stimulation. Strikingly, RSE took place even after reversal of LTP or LTD, that is, the same synapse can display different levels of short-term plasticity without changing Synaptic Efficacy for the initial spike in burst preSynaptic firing, thereby modulating spike transmission in a firing rate-dependent manner. Thus, the history of long-term Synaptic plasticity is registered in the form of short-term plasticity, and RSE extends the information storage capacity of a synapse and adds another dimension of functional complexity to neuronal operations.
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Dynamic synapses as archives of Synaptic history: state-dependent redistribution of Synaptic Efficacy in the rat hippocampal CA1.
The Journal of physiology, 2005Co-Authors: Takuya Yasui, Shigeyoshi Fujisawa, Masako Tsukamoto, Norio Matsuki, Yuji IkegayaAbstract:Plastic modifications of Synaptic strength are putative mechanisms underlying information processing in the brain, including memory storage, signal integration and filtering. Here we describe a dynamic interplay between short-term and long-term Synaptic plasticity. At rat hippocampal CA1 synapses, induction of both long-term potentiation (LTP) and depression (LTD) was accompanied by changes in the profile of short-term plasticity, termed redistribution of Synaptic Efficacy (RSE). RSE was preSynaptically expressed and associated in part with a persistent alteration in hyperpolarization-activated I(h) channel activity. Already potentiated synapses were still capable of showing RSE in response to additional LTP-triggering stimulation. Strikingly, RSE took place even after reversal of LTP or LTD, that is, the same synapse can display different levels of short-term plasticity without changing Synaptic Efficacy for the initial spike in burst preSynaptic firing, thereby modulating spike transmission in a firing rate-dependent manner. Thus, the history of long-term Synaptic plasticity is registered in the form of short-term plasticity, and RSE extends the information storage capacity of a synapse and adds another dimension of functional complexity to neuronal operations.
