The Experts below are selected from a list of 6537 Experts worldwide ranked by ideXlab platform
Wulfram Gerstner - One of the best experts on this subject based on the ideXlab platform.
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optimal spike timing dependent plasticity for precise action Potential firing in supervised learning
Neural Computation, 2006Co-Authors: Jeanpascal Pfister, Taro Toyoizumi, David Barber, Wulfram GerstnerAbstract:In timing-based neural codes, neurons have to emit action Potentials at precise moments in time. We use a supervised learning paradigm to derive a synaptic update rule that optimizes by gradient ascent the likelihood of Postsynaptic firing at one or several desired firing times. We find that the optimal strategy of up- and downregulating synaptic efficacies depends on the relative timing between presynaptic spike arrival and desired Postsynaptic firing. If the presynaptic spike arrives before the desired Postsynaptic spike timing, our optimal learning rule predicts that the synapse should become potentiated. The dependence of the potentiation on spike timing directly reflects the time course of an Excitatory Postsynaptic Potential. However, our approach gives no unique reason for synaptic depression under reversed spike timing. In fact, the presence and amplitude of depression of synaptic efficacies for reversed spike timing depend on how constraints are implemented in the optimization problem. Two different constraints, control of Postsynaptic rates and control of temporal locality, are studied. The relation of our results to spike-timing-dependent plasticity and reinforcement learning is discussed.
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optimal spike timing dependent plasticity for precise action Potential firing
arXiv: Neurons and Cognition, 2005Co-Authors: Jeanpascal Pfister, Taro Toyoizumi, David Barber, Wulfram GerstnerAbstract:In timing-based neural codes, neurons have to emit action Potentials at precise moments in time. We use a supervised learning paradigm to derive a synaptic update rule that optimizes via gradient ascent the likelihood of Postsynaptic firing at one or several desired firing times. We find that the optimal strategy of up- and downregulating synaptic efficacies can be described by a two-phase learning window similar to that of Spike-Timing Dependent Plasticity (STDP). If the presynaptic spike arrives before the desired Postsynaptic spike timing, our optimal learning rule predicts that the synapse should become potentiated. The dependence of the potentiation on spike timing directly reflects the time course of an Excitatory Postsynaptic Potential. The presence and amplitude of depression of synaptic efficacies for reversed spike timing depends on how constraints are implemented in the optimization problem. Two different constraints, i.e., control of Postsynaptic rates or control of temporal locality,are discussed.
Janice M Hoesing - One of the best experts on this subject based on the ideXlab platform.
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induction of long term potentiation at perforant path dentate synapses does not affect place learning or memory
Hippocampus, 1993Co-Authors: Robert J Sutherland, Hans C Dringenberg, Janice M HoesingAbstract:In two experiments the authors failed to detect an effect of inducing bilateral, long-lasting synaptic potentiation at perforant path dentate synapses on spatial learning by rats in the Morris place navigation task. Daily sessions of high-frequency stimulation of perforant path axons produced large increases to an asymptotic level in population spike and field Excitatory Postsynaptic Potential recorded in ipsilateral dentate gyrus. Place learning proceeded normally 24 hours after the last of 14 high-frequency stimulation sessions in rats that had previously mastered the procedural aspects of place navigation (Experiment 1) and in rats that were naive (Experiment 2).
Jeanpascal Pfister - One of the best experts on this subject based on the ideXlab platform.
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optimal spike timing dependent plasticity for precise action Potential firing in supervised learning
Neural Computation, 2006Co-Authors: Jeanpascal Pfister, Taro Toyoizumi, David Barber, Wulfram GerstnerAbstract:In timing-based neural codes, neurons have to emit action Potentials at precise moments in time. We use a supervised learning paradigm to derive a synaptic update rule that optimizes by gradient ascent the likelihood of Postsynaptic firing at one or several desired firing times. We find that the optimal strategy of up- and downregulating synaptic efficacies depends on the relative timing between presynaptic spike arrival and desired Postsynaptic firing. If the presynaptic spike arrives before the desired Postsynaptic spike timing, our optimal learning rule predicts that the synapse should become potentiated. The dependence of the potentiation on spike timing directly reflects the time course of an Excitatory Postsynaptic Potential. However, our approach gives no unique reason for synaptic depression under reversed spike timing. In fact, the presence and amplitude of depression of synaptic efficacies for reversed spike timing depend on how constraints are implemented in the optimization problem. Two different constraints, control of Postsynaptic rates and control of temporal locality, are studied. The relation of our results to spike-timing-dependent plasticity and reinforcement learning is discussed.
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optimal spike timing dependent plasticity for precise action Potential firing
arXiv: Neurons and Cognition, 2005Co-Authors: Jeanpascal Pfister, Taro Toyoizumi, David Barber, Wulfram GerstnerAbstract:In timing-based neural codes, neurons have to emit action Potentials at precise moments in time. We use a supervised learning paradigm to derive a synaptic update rule that optimizes via gradient ascent the likelihood of Postsynaptic firing at one or several desired firing times. We find that the optimal strategy of up- and downregulating synaptic efficacies can be described by a two-phase learning window similar to that of Spike-Timing Dependent Plasticity (STDP). If the presynaptic spike arrives before the desired Postsynaptic spike timing, our optimal learning rule predicts that the synapse should become potentiated. The dependence of the potentiation on spike timing directly reflects the time course of an Excitatory Postsynaptic Potential. The presence and amplitude of depression of synaptic efficacies for reversed spike timing depends on how constraints are implemented in the optimization problem. Two different constraints, i.e., control of Postsynaptic rates or control of temporal locality,are discussed.
Robert J Sutherland - One of the best experts on this subject based on the ideXlab platform.
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induction of long term potentiation at perforant path dentate synapses does not affect place learning or memory
Hippocampus, 1993Co-Authors: Robert J Sutherland, Hans C Dringenberg, Janice M HoesingAbstract:In two experiments the authors failed to detect an effect of inducing bilateral, long-lasting synaptic potentiation at perforant path dentate synapses on spatial learning by rats in the Morris place navigation task. Daily sessions of high-frequency stimulation of perforant path axons produced large increases to an asymptotic level in population spike and field Excitatory Postsynaptic Potential recorded in ipsilateral dentate gyrus. Place learning proceeded normally 24 hours after the last of 14 high-frequency stimulation sessions in rats that had previously mastered the procedural aspects of place navigation (Experiment 1) and in rats that were naive (Experiment 2).
Howard V. Wheal - One of the best experts on this subject based on the ideXlab platform.
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reversal of Excitatory Postsynaptic Potential spike potentiation in the ca1 area of the rat hippocampus
Neuroscience, 1998Co-Authors: Christophe Bernard, J Pickering, Howard V. WhealAbstract:Abstract In the CA1 area of the hippocampus, low frequency and tetanic conditioning stimuli are known to trigger long-term depression and potentiation of synaptic responses respectively and to produce irreversible Excitatory Postsynaptic Potential/spike potentiation, i.e. an increase of the probability of discharge of the neurons. Using simultaneous extracellular recordings in stratum radiatum and stratum pyramidale in the CA1 area of the rat hippocampus, brief application of the K+ channel blocker tetraethylammonium resulted both in long-term potentiation of synaptic responses and in Excitatory Postsynaptic Potential/spike potentiation that could be reversed by subsequent low frequency or tetanic stimuli. Excitatory Postsynaptic Potential/spike potentiation and its subsequent reversal by an electrical conditioning stimulus were found to have an N-methyl- d -aspartate receptor-independent component. We conclude that the reversal of Excitatory Postsynaptic Potential/spike potentiation can occur and that it does not require the induction of long-term modification of synaptic responses.
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simultaneous expression of Excitatory Postsynaptic Potential spike potentiation and Excitatory Postsynaptic Potential spike depression in the hippocampus
Neuroscience, 1995Co-Authors: Christophe Bernard, Howard V. WhealAbstract:Abstract Tetanic stimulation of afferents in the stratum radiatum of the CA1 area of the rat hippocampus results in long-term potentiation of Excitatory synaptic responses in pyramidal cells. Previous studies have reported a greater increase in the population spike amplitude following the induction of long-term potentiation than could be accounted for by the increase of the slope of the population Excitatory Postsynaptic Potential. Two hypotheses have been proposed to explain this phenomenon (called Excitatory Postsynaptic Potential/spike potentiation): a modification of the firing threshold and/or a modification of the inhibitory drive. Previous studies have not, however, addressed the question of possible changes in spike threshold in association with long-term depression. This paper examines whether the concomitant long-term potentiation of pharmacologically isolated N -methyl- d -aspartate receptor-mediated Excitatory Postsynaptic Potentials, reported previously, is also associated with a change in spike threshold. When the amplitude of the population spike is plotted as a function of the slope of the population Excitatory Postsynaptic Potential (Excitatory Postsynaptic Potential/spike curve), Excitatory Postsynaptic Potential/ spike potentiation (depression) is seen as a shift of the Excitatory Postsynaptic Potential/spike curve to the left (right) following a conditioning stimulus. In this study, using kainic acid lesioned hippocampus, we have shown that tetanic stimulation produced Excitatory Postsynaptic Potential/spike potentiation of the control synaptic response and Excitatory Postsynaptic Potential/spike depression of the isolated N -methyl- d -aspartate receptor-mediated responses.
