The Experts below are selected from a list of 11862 Experts worldwide ranked by ideXlab platform
Washington Buno - One of the best experts on this subject based on the ideXlab platform.
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changes of the epsp waveform regulate the Temporal Window for spike timing dependent plasticity
The Journal of Neuroscience, 2007Co-Authors: Marco Fuenzalida, David Fernandez De Sevilla, Washington BunoAbstract:Using spike-timing-dependent plasticity (STDP) protocols that consist of pairing an EPSP and a postsynaptic backpropagating action potential (BAP), we investigated the contribution of the changes in EPSP waveform induced by the slow Ca 2+ -dependent K + -mediated afterhyperpolarization (sAHP) in the regulation of long-term potentiation (LTP). The “Temporal Window” between Schaffer collateral EPSPs and BAPs in CA1 pyramidal neurons required to induce LTP was narrowed by a reduction of the amplitude and decay time constant of the EPSP, which could be reversed with cyclothiazide. The EPSP changes were caused by the increased conductance induced by activation of the sAHP. Therefore, the EPSP waveform and its regulation by the sAHP are central in determining the duration of the Temporal Window for STDP, thus providing a possible dynamic regulatory mechanism for the encoding of cognitive processes.
Huibert D Mansvelder - One of the best experts on this subject based on the ideXlab platform.
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human synapses show a wide Temporal Window for spike timing dependent plasticity
Frontiers in Synaptic Neuroscience, 2010Co-Authors: Guilherme Testasilva, Matthijs B Verhoog, Natalia A Goriounova, Alex Loebel, J Johannes J Hjorth, Johannes C Baayen, C P J De Kock, Huibert D MansvelderAbstract:Throughout our lifetime, activity-dependent changes in neuronal connection strength enable the brain to refine neural circuits and learn based on experience. Synapses can bi-directionally alter strength and the magnitude and sign depend on the millisecond timing of presynaptic and postsynaptic action potential firing. Recent findings on laboratory animals have shown that neurons can show a variety of Temporal Windows for spike-timing-dependent plasticity (STDP). It is unknown what synaptic learning rules exist in human synapses and whether similar Temporal Windows for STDP at synapses hold true for the human brain. Here, we directly tested in human slices cut from hippocampal tissue removed for surgical treatment of deeper brain structures in drug-resistant epilepsy patients, whether adult human synapses can change strength in response to millisecond timing of pre- and postsynaptic firing. We find that adult human hippocampal synapses can alter synapse strength in response to timed pre- and postsynaptic activity. In contrast to rodent hippocampal synapses, the sign of plasticity does not sharply switch around 0 millisecond timing. Instead, both positive timing intervals, in which presynaptic firing preceded the postsynaptic action potential, and negative timing intervals, in which postsynaptic firing preceded presynaptic activity down to -80 ms, increase synapse strength (tLTP). Negative timing intervals between -80 to -130 ms induce a lasting reduction of synapse strength (tLTD). Thus, similar to rodent synapses, adult human synapses can show spike-timing-dependent changes in strength. The timing rules of STDP in human hippocampus, however, seem to differ from rodent hippocampus, and suggest a less strict interpretation of Hebb’s predictions.
Luc Van Gool - One of the best experts on this subject based on the ideXlab platform.
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ICCV - Online Video SEEDS for Temporal Window Objectness
2013 IEEE International Conference on Computer Vision, 2013Co-Authors: Michael Van Den Bergh, Gemma Roig, Xavier Boix, Santiago Manen, Luc Van GoolAbstract:Super pixel and objectness algorithms are broadly used as a pre-processing step to generate support regions and to speed-up further computations. Recently, many algorithms have been extended to video in order to exploit the Temporal consistency between frames. However, most methods are computationally too expensive for real-time applications. We introduce an online, real-time video super pixel algorithm based on the recently proposed SEEDS super pixels. A new capability is incorporated which delivers multiple diverse samples (hypotheses) of super pixels in the same image or video sequence. The multiple samples are shown to provide a strong cue to efficiently measure the objectness of image Windows, and we introduce the novel concept of objectness in Temporal Windows. Experiments show that the video super pixels achieve comparable performance to state-of-the-art offline methods while running at 30 fps on a single 2.8 GHz i7 CPU. State-of-the-art performance on objectness is also demonstrated, yet orders of magnitude faster and extended to Temporal Windows in video.
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Online Video SEEDS for Temporal Window Objectness
2013 IEEE International Conference on Computer Vision, 2013Co-Authors: Michael Van Den Bergh, Gemma Roig, Xavier Boix, Santiago Manen, Luc Van GoolAbstract:Super pixel and objectness algorithms are broadly used as a pre-processing step to generate support regions and to speed-up further computations. Recently, many algorithms have been extended to video in order to exploit the Temporal consistency between frames. However, most methods are computationally too expensive for real-time applications. We introduce an online, real-time video super pixel algorithm based on the recently proposed SEEDS super pixels. A new capability is incorporated which delivers multiple diverse samples (hypotheses) of super pixels in the same image or video sequence. The multiple samples are shown to provide a strong cue to efficiently measure the objectness of image Windows, and we introduce the novel concept of objectness in Temporal Windows. Experiments show that the video super pixels achieve comparable performance to state-of-the-art offline methods while running at 30 fps on a single 2.8 GHz i7 CPU. State-of-the-art performance on objectness is also demonstrated, yet orders of magnitude faster and extended to Temporal Windows in video.
Marco Fuenzalida - One of the best experts on this subject based on the ideXlab platform.
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changes of the epsp waveform regulate the Temporal Window for spike timing dependent plasticity
The Journal of Neuroscience, 2007Co-Authors: Marco Fuenzalida, David Fernandez De Sevilla, Washington BunoAbstract:Using spike-timing-dependent plasticity (STDP) protocols that consist of pairing an EPSP and a postsynaptic backpropagating action potential (BAP), we investigated the contribution of the changes in EPSP waveform induced by the slow Ca 2+ -dependent K + -mediated afterhyperpolarization (sAHP) in the regulation of long-term potentiation (LTP). The “Temporal Window” between Schaffer collateral EPSPs and BAPs in CA1 pyramidal neurons required to induce LTP was narrowed by a reduction of the amplitude and decay time constant of the EPSP, which could be reversed with cyclothiazide. The EPSP changes were caused by the increased conductance induced by activation of the sAHP. Therefore, the EPSP waveform and its regulation by the sAHP are central in determining the duration of the Temporal Window for STDP, thus providing a possible dynamic regulatory mechanism for the encoding of cognitive processes.
Guilherme Testasilva - One of the best experts on this subject based on the ideXlab platform.
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human synapses show a wide Temporal Window for spike timing dependent plasticity
Frontiers in Synaptic Neuroscience, 2010Co-Authors: Guilherme Testasilva, Matthijs B Verhoog, Natalia A Goriounova, Alex Loebel, J Johannes J Hjorth, Johannes C Baayen, C P J De Kock, Huibert D MansvelderAbstract:Throughout our lifetime, activity-dependent changes in neuronal connection strength enable the brain to refine neural circuits and learn based on experience. Synapses can bi-directionally alter strength and the magnitude and sign depend on the millisecond timing of presynaptic and postsynaptic action potential firing. Recent findings on laboratory animals have shown that neurons can show a variety of Temporal Windows for spike-timing-dependent plasticity (STDP). It is unknown what synaptic learning rules exist in human synapses and whether similar Temporal Windows for STDP at synapses hold true for the human brain. Here, we directly tested in human slices cut from hippocampal tissue removed for surgical treatment of deeper brain structures in drug-resistant epilepsy patients, whether adult human synapses can change strength in response to millisecond timing of pre- and postsynaptic firing. We find that adult human hippocampal synapses can alter synapse strength in response to timed pre- and postsynaptic activity. In contrast to rodent hippocampal synapses, the sign of plasticity does not sharply switch around 0 millisecond timing. Instead, both positive timing intervals, in which presynaptic firing preceded the postsynaptic action potential, and negative timing intervals, in which postsynaptic firing preceded presynaptic activity down to -80 ms, increase synapse strength (tLTP). Negative timing intervals between -80 to -130 ms induce a lasting reduction of synapse strength (tLTD). Thus, similar to rodent synapses, adult human synapses can show spike-timing-dependent changes in strength. The timing rules of STDP in human hippocampus, however, seem to differ from rodent hippocampus, and suggest a less strict interpretation of Hebb’s predictions.
