The Experts below are selected from a list of 138 Experts worldwide ranked by ideXlab platform
Roger A Nicoll - One of the best experts on this subject based on the ideXlab platform.
-
erratum silent synapses and the emergence of a Postsynaptic Mechanism for ltp
Nature Reviews Neuroscience, 2009Co-Authors: Geoffrey A Kerchner, Roger A NicollAbstract:Nature Reviews Neuroscience 9, 813–825 (2008) In the above article, an important reference was omitted and appropriate credit was not given for the first observation of silent synapses by laser-evoked glutamate uncaging on to single, visually identified dendritic spines. In the rat hippocampal CA1 region, Beique et al.
-
silent synapses and the emergence of a Postsynaptic Mechanism for ltp
Nature Reviews Neuroscience, 2008Co-Authors: Geoffrey A Kerchner, Roger A NicollAbstract:Silent synapses abound in the young brain, representing an early step in the pathway of experience-dependent synaptic development. Discovered amidst the debate over whether long-term potentiation reflects a presynaptic or a Postsynaptic modification, silent synapses — which in the hippocampal CA1 subfield are characterized by the presence of NMDA receptors but not AMPA receptors — have stirred some mechanistic controversy of their own. Out of this literature has emerged a model for synapse unsilencing that highlights the central role for Postsynaptic AMPA-receptor trafficking in the expression of excitatory synaptic plasticity.
Geoffrey A Kerchner - One of the best experts on this subject based on the ideXlab platform.
-
erratum silent synapses and the emergence of a Postsynaptic Mechanism for ltp
Nature Reviews Neuroscience, 2009Co-Authors: Geoffrey A Kerchner, Roger A NicollAbstract:Nature Reviews Neuroscience 9, 813–825 (2008) In the above article, an important reference was omitted and appropriate credit was not given for the first observation of silent synapses by laser-evoked glutamate uncaging on to single, visually identified dendritic spines. In the rat hippocampal CA1 region, Beique et al.
-
silent synapses and the emergence of a Postsynaptic Mechanism for ltp
Nature Reviews Neuroscience, 2008Co-Authors: Geoffrey A Kerchner, Roger A NicollAbstract:Silent synapses abound in the young brain, representing an early step in the pathway of experience-dependent synaptic development. Discovered amidst the debate over whether long-term potentiation reflects a presynaptic or a Postsynaptic modification, silent synapses — which in the hippocampal CA1 subfield are characterized by the presence of NMDA receptors but not AMPA receptors — have stirred some mechanistic controversy of their own. Out of this literature has emerged a model for synapse unsilencing that highlights the central role for Postsynaptic AMPA-receptor trafficking in the expression of excitatory synaptic plasticity.
J. Gerard G. Borst - One of the best experts on this subject based on the ideXlab platform.
-
Short-term plasticity at the calyx of held
Nature Reviews Neuroscience, 2002Co-Authors: Henrique Von Gersdorff, J. Gerard G. BorstAbstract:The Mechanisms that underlie short-term synaptic plasticity are beginning to be understood. Modifications of the pre- or the Postsynaptic elements can account for transient changes in the efficacy of synapses, but presynaptic changes have been particularly difficult to document, owing to the small size of the axon terminal. The calyx of Held — a synapse of the auditory brainstem — has been a good model for the study of presynaptic Mechanisms of plasticity, chiefly because of its large size, which makes it accessible to direct experimental manipulations. The calyx of Held undergoes marked morphological and physiological changes during development. They take place both pre- and Postsynaptically, and allow this synaptic contact to be extraordinarily fast and reliable. The calyx of Held is involved in sound localization, and its speed is crucial for the accuracy required in performing this function. Although calcium-dependent, short-term facilitation has been observed at the calyx of Held, most experimental attention has centred on the Mechanisms of short-term depression. Pre- and Postsynaptic Mechanisms have been proposed to explain depression; their relative contributions depend on the frequency of stimulation. Possible presynaptic Mechanisms of depression at the calyx of Held include changes in action potential waveform, inactivation of calcium currents and vesicle pool depletion. The evidence favours the idea that pool depletion is the most prominent Mechanism at this synaptic contact. Glutamate receptor saturation has been proposed, in turn, as a possible Postsynaptic Mechanism of depression, although the evidence indicates that receptor desensitization has a more significant role. Although short-term plasticity is prominent at the calyx of Held, its relevance to signal processing is unclear. Also, many related questions remain unanswered. How plastic is this synapse in adult animals? How much can the conclusions obtained in the calyx be extrapolated to bouton-type synapses? What Mechanisms modulate and control the kinetics of vesicle recycling? The experimental advantages that the calyx of Held offers will be instrumental in solving these riddles. Synapses show widely varying degrees of short-term facilitation and depression. Several Mechanisms have been proposed to underlie short-term plasticity, but the contributions of presynaptic Mechanisms have been particularly difficult to study because of the small size of synaptic boutons in the mammalian brain. Here we review the functional properties of the calyx of Held, a giant nerve terminal that has shed new light on the general Mechanisms that control short-term plasticity. The calyx of Held has also provided fresh insights into the strategies used by synapses to extend their dynamic range of operation and preserve the timing of sensory stimuli.
Thomas J Carew - One of the best experts on this subject based on the ideXlab platform.
-
a novel Postsynaptic Mechanism for heterosynaptic sharing of short term plasticity
The Journal of Neuroscience, 2010Co-Authors: Kathryn J Reissner, Lu Pu, Joanna H Schaffhausen, Heather D Boyle, Ian F Smith, Ian Parker, Thomas J CarewAbstract:Postsynaptic release of Ca2+ from intracellular stores is an important means of cellular signaling that mediates numerous forms of synaptic plasticity. Previous studies have identified a Postsynaptic intracellular Ca2+ requirement for a form of short-term plasticity, post-tetanic potentiation (PTP) at sensory neuron (SN)–motor neuron synapses in Aplysia. Here, we show that Postsynaptic IP3-mediated Ca2+ release in response to a presynaptic tetanus in an SN that induces PTP can confer transient plasticity onto a neighboring SN synapse receiving subthreshold activation. This heterosynaptic sharing of plasticity represents a dynamic, short-term synaptic enhancement of synaptic inputs onto a common Postsynaptic target. Heterosynaptic sharing is blocked by Postsynaptic disruption of Ca2+- and IP3-mediated signaling, and, conversely, it is mimicked by Postsynaptic injection of nonhydrolyzable IP3, and by photolysis of caged IP3 in the MN. The molecular Mechanism for heterosynaptic sharing involves metabotropic glutamate receptors and Homer-dependent interactions, indicating that Homer can facilitate the integration of Ca2+-dependent plasticity at neighboring Postsynaptic sites and provides a Postsynaptic Mechanism for the spread of plasticity induced by presynaptic activation. Our results support a model in which Postsynaptic summation of IP3 signals from suprathreshold and subthreshold inputs results in molecular coincidence detection that gives rise to a novel form of heterosynaptic plasticity.
Henrique Von Gersdorff - One of the best experts on this subject based on the ideXlab platform.
-
Short-term plasticity at the calyx of held
Nature Reviews Neuroscience, 2002Co-Authors: Henrique Von Gersdorff, J. Gerard G. BorstAbstract:The Mechanisms that underlie short-term synaptic plasticity are beginning to be understood. Modifications of the pre- or the Postsynaptic elements can account for transient changes in the efficacy of synapses, but presynaptic changes have been particularly difficult to document, owing to the small size of the axon terminal. The calyx of Held — a synapse of the auditory brainstem — has been a good model for the study of presynaptic Mechanisms of plasticity, chiefly because of its large size, which makes it accessible to direct experimental manipulations. The calyx of Held undergoes marked morphological and physiological changes during development. They take place both pre- and Postsynaptically, and allow this synaptic contact to be extraordinarily fast and reliable. The calyx of Held is involved in sound localization, and its speed is crucial for the accuracy required in performing this function. Although calcium-dependent, short-term facilitation has been observed at the calyx of Held, most experimental attention has centred on the Mechanisms of short-term depression. Pre- and Postsynaptic Mechanisms have been proposed to explain depression; their relative contributions depend on the frequency of stimulation. Possible presynaptic Mechanisms of depression at the calyx of Held include changes in action potential waveform, inactivation of calcium currents and vesicle pool depletion. The evidence favours the idea that pool depletion is the most prominent Mechanism at this synaptic contact. Glutamate receptor saturation has been proposed, in turn, as a possible Postsynaptic Mechanism of depression, although the evidence indicates that receptor desensitization has a more significant role. Although short-term plasticity is prominent at the calyx of Held, its relevance to signal processing is unclear. Also, many related questions remain unanswered. How plastic is this synapse in adult animals? How much can the conclusions obtained in the calyx be extrapolated to bouton-type synapses? What Mechanisms modulate and control the kinetics of vesicle recycling? The experimental advantages that the calyx of Held offers will be instrumental in solving these riddles. Synapses show widely varying degrees of short-term facilitation and depression. Several Mechanisms have been proposed to underlie short-term plasticity, but the contributions of presynaptic Mechanisms have been particularly difficult to study because of the small size of synaptic boutons in the mammalian brain. Here we review the functional properties of the calyx of Held, a giant nerve terminal that has shed new light on the general Mechanisms that control short-term plasticity. The calyx of Held has also provided fresh insights into the strategies used by synapses to extend their dynamic range of operation and preserve the timing of sensory stimuli.
