The Experts below are selected from a list of 51 Experts worldwide ranked by ideXlab platform

Anders Lansner - One of the best experts on this subject based on the ideXlab platform.

  • Long-range recruitment of Martinotti Cells causes surround suppression and promotes saliency in an attractor network model.
    Frontiers in neural circuits, 2015
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    Although the importance of long-range connections for cortical information processing has been acknowledged for a long time, most studies focused on the long-range interactions between excitatory cortical neurons. Inhibitory interneurons play an important role in cortical computation and have thus far been studied mainly with respect to their local synaptic interactions within the cortical microcircuitry. A recent study showed that long-range excitatory connections onto Martinotti Cells (MC) mediate surround suppression. Here we have extended our previously reported attractor network of pyramidal Cells (PC) and MC by introducing long-range connections targeting MC. We have demonstrated how the network with Martinotti Cell-mediated long-range inhibition gives rise to surround suppression and also promotes saliency of locations at which simple non-uniformities in the stimulus field are introduced. Furthermore, our analysis suggests that the presynaptic dynamics of MC is only ancillary to its orientation tuning property in enabling the network with saliency detection. Lastly, we have also implemented a disinhibitory pathway mediated by another interneuron type (VIP interneurons), which inhibits MC and abolishes surround suppression.

  • A Cortical Attractor Network with Martinotti Cells Driven by Facilitating Synapses
    2013
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    The population of pyramidal Cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal Cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal Cells. The Martinotti Cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal Cells. This distinguishes these neurons from basket Cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal Cells via one or a few Martinotti Cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket Cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti Cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti Cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical spee

  • A cortical attractor network with Martinotti Cells driven by facilitating synapses
    PloS one, 2012
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    The population of pyramidal Cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal Cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal Cells. The Martinotti Cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal Cells. This distinguishes these neurons from basket Cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal Cells via one or a few Martinotti Cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket Cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti Cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti Cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical speed of processing, with Cellular adaptation and synaptic depression having a less prominent role than previously thought.

Pradeep Krishnamurthy - One of the best experts on this subject based on the ideXlab platform.

  • Long-range recruitment of Martinotti Cells causes surround suppression and promotes saliency in an attractor network model.
    Frontiers in neural circuits, 2015
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    Although the importance of long-range connections for cortical information processing has been acknowledged for a long time, most studies focused on the long-range interactions between excitatory cortical neurons. Inhibitory interneurons play an important role in cortical computation and have thus far been studied mainly with respect to their local synaptic interactions within the cortical microcircuitry. A recent study showed that long-range excitatory connections onto Martinotti Cells (MC) mediate surround suppression. Here we have extended our previously reported attractor network of pyramidal Cells (PC) and MC by introducing long-range connections targeting MC. We have demonstrated how the network with Martinotti Cell-mediated long-range inhibition gives rise to surround suppression and also promotes saliency of locations at which simple non-uniformities in the stimulus field are introduced. Furthermore, our analysis suggests that the presynaptic dynamics of MC is only ancillary to its orientation tuning property in enabling the network with saliency detection. Lastly, we have also implemented a disinhibitory pathway mediated by another interneuron type (VIP interneurons), which inhibits MC and abolishes surround suppression.

  • A Cortical Attractor Network with Martinotti Cells Driven by Facilitating Synapses
    2013
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    The population of pyramidal Cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal Cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal Cells. The Martinotti Cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal Cells. This distinguishes these neurons from basket Cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal Cells via one or a few Martinotti Cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket Cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti Cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti Cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical spee

  • A cortical attractor network with Martinotti Cells driven by facilitating synapses
    PloS one, 2012
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    The population of pyramidal Cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal Cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal Cells. The Martinotti Cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal Cells. This distinguishes these neurons from basket Cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal Cells via one or a few Martinotti Cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket Cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti Cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti Cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical speed of processing, with Cellular adaptation and synaptic depression having a less prominent role than previously thought.

Gilad Silberberg - One of the best experts on this subject based on the ideXlab platform.

  • Long-range recruitment of Martinotti Cells causes surround suppression and promotes saliency in an attractor network model.
    Frontiers in neural circuits, 2015
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    Although the importance of long-range connections for cortical information processing has been acknowledged for a long time, most studies focused on the long-range interactions between excitatory cortical neurons. Inhibitory interneurons play an important role in cortical computation and have thus far been studied mainly with respect to their local synaptic interactions within the cortical microcircuitry. A recent study showed that long-range excitatory connections onto Martinotti Cells (MC) mediate surround suppression. Here we have extended our previously reported attractor network of pyramidal Cells (PC) and MC by introducing long-range connections targeting MC. We have demonstrated how the network with Martinotti Cell-mediated long-range inhibition gives rise to surround suppression and also promotes saliency of locations at which simple non-uniformities in the stimulus field are introduced. Furthermore, our analysis suggests that the presynaptic dynamics of MC is only ancillary to its orientation tuning property in enabling the network with saliency detection. Lastly, we have also implemented a disinhibitory pathway mediated by another interneuron type (VIP interneurons), which inhibits MC and abolishes surround suppression.

  • A Cortical Attractor Network with Martinotti Cells Driven by Facilitating Synapses
    2013
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    The population of pyramidal Cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal Cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal Cells. The Martinotti Cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal Cells. This distinguishes these neurons from basket Cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal Cells via one or a few Martinotti Cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket Cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti Cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti Cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical spee

  • A cortical attractor network with Martinotti Cells driven by facilitating synapses
    PloS one, 2012
    Co-Authors: Pradeep Krishnamurthy, Gilad Silberberg, Anders Lansner
    Abstract:

    The population of pyramidal Cells significantly outnumbers the inhibitory interneurons in the neocortex, while at the same time the diversity of interneuron types is much more pronounced. One acknowledged key role of inhibition is to control the rate and patterning of pyramidal Cell firing via negative feedback, but most likely the diversity of inhibitory pathways is matched by a corresponding diversity of functional roles. An important distinguishing feature of cortical interneurons is the variability of the short-term plasticity properties of synapses received from pyramidal Cells. The Martinotti Cell type has recently come under scrutiny due to the distinctly facilitating nature of the synapses they receive from pyramidal Cells. This distinguishes these neurons from basket Cells and other inhibitory interneurons typically targeted by depressing synapses. A key aspect of the work reported here has been to pinpoint the role of this variability. We first set out to reproduce quantitatively based on in vitro data the di-synaptic inhibitory microcircuit connecting two pyramidal Cells via one or a few Martinotti Cells. In a second step, we embedded this microcircuit in a previously developed attractor memory network model of neocortical layers 2/3. This model network demonstrated that basket Cells with their characteristic depressing synapses are the first to discharge when the network enters an attractor state and that Martinotti Cells respond with a delay, thereby shifting the excitation-inhibition balance and acting to terminate the attractor state. A parameter sensitivity analysis suggested that Martinotti Cells might, in fact, play a dominant role in setting the attractor dwell time and thus cortical speed of processing, with Cellular adaptation and synaptic depression having a less prominent role than previously thought.

Desdemona Fricker - One of the best experts on this subject based on the ideXlab platform.

  • Activity dependent feedback inhibition may maintain head direction signals in mouse presubiculum
    Nature Communications, 2017
    Co-Authors: Jean Simonnet, Mérie Nassar, Federico Stella, Ivan Cohen, Bertrand Mathon, Charlotte N. Boccara, Richard Miles, Desdemona Fricker
    Abstract:

    Head direction is encoded by Cells in the presubiculum, but the role of local circuitry in head direction encoding remains unknown. Here the authors demonstrate how a specific inhibitory neuron type, the Martinotti Cell, together with excitatory pyramidal Cells supports head direction signals. Orientation in space is represented in specialized brain circuits. Persistent head direction signals are transmitted from anterior thalamus to the presubiculum, but the identity of the presubicular target neurons, their connectivity and function in local microcircuits are unknown. Here, we examine how thalamic afferents recruit presubicular principal neurons and Martinotti interneurons, and the ensuing synaptic interactions between these Cells. Pyramidal neuron activation of Martinotti Cells in superficial layers is strongly facilitating such that high-frequency head directional stimulation efficiently unmutes synaptic excitation. Martinotti-Cell feedback plays a dual role: precisely timed spikes may not inhibit the firing of in-tune head direction Cells, while exerting lateral inhibition. Autonomous attractor dynamics emerge from a modelled network implementing wiring motifs and timing sensitive synaptic interactions in the pyramidal—Martinotti-Cell feedback loop. This inhibitory microcircuit is therefore tuned to refine and maintain head direction information in the presubiculum.

  • How activity dependent feedback inhibition may maintain head direction signals in mouse presubiculum
    2017
    Co-Authors: Jean Simonnet, Mérie Nassar, Federico Stella, Ivan Cohen, Bertrand Mathon, Charlotte N. Boccara, Richard B. Miles, Desdemona Fricker
    Abstract:

    Orientation in space is represented in specialized brain circuits. Persistent head direction signals are transmitted from anterior thalamus to the presubiculum, but the identity of the presubicular target neurons, their connectivity and function in local microcircuits are unknown. Here we examine how thalamic afferents recruit presubicular principal neurons and Martinotti interneurons and the ensuing synaptic interactions between these Cells. Pyramidal neuron activation of Martinotti Cells in superficial layers is strongly facilitating such that high frequency head directional stimulation efficiently unmutes synaptic excitation. Martinotti Cell feedback plays a dual role: precisely timed spikes may not inhibit the firing of in-tune head direction Cells, while exerting lateral inhibition. Autonomous attractor dynamics emerge from a modeled network implementing wiring motifs and timing sensitive synaptic interactions in the pyramidal - Martinotti Cell feedback loop. This inhibitory microcircuit is therefore tuned to refine and maintain head direction information in the presubiculum.

Anders Elansner - One of the best experts on this subject based on the ideXlab platform.

  • Long-range inhibition mediated by Martinotti Cells causes surround suppression and promotes saliency in an attractor network model
    Frontiers Media S.A., 2015
    Co-Authors: Pradeep Ekrishnamurthy, Gilad Esilberberg, Anders Elansner
    Abstract:

    Although the importance of long-range connections for cortical information processing has been acknowledged for a long time, most studies focused on the long-range interactions between excitatory cortical neurons. Inhibitory interneurons play an important role in cortical computation and have thus far been studied mainly with respect to their local synaptic interactions within the cortical microcircuitry. A recent study showed that long-range excitatory connections onto Martinotti Cells mediate surround suppression. Here we have extended our previously reported attractor network of pyramidal and Martinotti Cells by introducing long-range connections targeting Martinotti Cells. We have demonstrated how the network with Martinotti Cell-mediated long-range inhibition gives rise to surround suppression and also promotes saliency of locations at which simple non-uniformities in the stimulus field are introduced. Furthermore, our analysis suggests that the presynaptic dynamics of Martinotti Cells is only ancillary to its orientation tuning property in enabling the network with saliency detection. Lastly, we have also implemented a disinhibitory pathway mediated by another interneuron type (VIP interneurons), which inhibits Martinotti Cells and abolishes surround suppression