The Experts below are selected from a list of 9789 Experts worldwide ranked by ideXlab platform
Donald A Glaser - One of the best experts on this subject based on the ideXlab platform.
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synaptic depression and facilitation can induce motion aftereffects in an Excitable Membrane model of visual motion processing
Neurocomputing, 2002Co-Authors: Donald A GlaserAbstract:Abstract A two-dimensional sheet of locally connected neural elements may be used to model motion detection in visual cortex. Activity waves resulting from inputs representing objects in motion have distinctive amplitudes and shapes, which characterize the object's motion. Repeated application of moving stimuli to such a system may lead to depression and facilitation of connections in the Membrane. As a consequence, nonmoving stimuli may then give rise to activity waves like those characteristic of motion, but in the direction opposite to that of the conditioning stimulus. This effect may be used to model translational and rotational motion aftereffects in visual cortex.
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slowly moving stimuli induce characteristic periodic activity waves in an Excitable Membrane model of visual motion processing
Neurocomputing, 2002Co-Authors: Donald A GlaserAbstract:Abstract A two-dimensional sheet of locally connected neural elements may be used to model motion detection in visual cortex. External inputs applied to such a system give rise to activity waves, which propagate with a speed determined by the Membrane parameters. Membrane inputs which are moving at a speed less than this intrinsic propagation rate give rise to periodic activity waves, which outrun the stimulus. The spacing between these waves is compressed in front of the stimulus, and expanded behind it, in a Doppler-like fashion. The wave frequency may be used to characterize the speed of the stimulus.
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motion detection and characterization by an Excitable Membrane the bow wave model
Neurocomputing, 1999Co-Authors: Donald A GlaserAbstract:Abstract We present a novel method for detecting and characterizing coherent motion in a set of image frames, using a two-dimensional sheet of locally connected neural elements. Externally applied activity leads to traveling activity waves. Activity waves resulting from points or objects in motion have a characteristic “bow wave” shape, which can be used to establish the existence, direction and speed of the object's motion. This mechanism may be used to model motion detection in biological systems, and may help to explain such psychophysical effects as motion pop-out, robustness of motion signals to noise, and the perception of transparent motion.
Marcel Horning - One of the best experts on this subject based on the ideXlab platform.
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three dimensional cell geometry controls Excitable Membrane signaling in dictyostelium cells
Biophysical Journal, 2019Co-Authors: Marcel Horning, Tatsuo ShibataAbstract:Abstract Phosphatidylinositol (3–5)-trisphosphate (PtdInsP3) is known to propagate as waves on the plasma Membrane and is related to the Membrane-protrusive activities in Dictyostelium and mammalian cells. Although there have been a few attempts to study the three-dimensional (3D) dynamics of these processes, most studies have focused on the dynamics extracted from single focal planes. However, the relation between the dynamics and 3D cell shape remains elusive because of the lack of signaling information about the unobserved part of the Membrane. Here, we show that PtdInsP3 wave dynamics are directly regulated by the 3D geometry (i.e., size and shape) of the plasma Membrane. By introducing an analysis method that extracts the 3D spatiotemporal activities on the entire cell Membrane, we show that PtdInsP3 waves self-regulate their dynamics within the confined Membrane area. This leads to changes in speed, orientation, and pattern evolution, following the underlying excitability of the signal transduction system. Our findings emphasize the role of the plasma Membrane topology in reaction-diffusion-driven biological systems and indicate its importance in other mammalian systems.
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three dimensional cell geometry controls Excitable Membrane signaling in dictyotelium cells
bioRxiv, 2018Co-Authors: Marcel Horning, Tatsuo ShibataAbstract:Phosphatidylinositol (3,4,5)-trisphosphate (PtdInsP3) is known to propagate as waves on the plasma Membrane and is related to the Membrane protrusive activities in Dictyostelium and mammalian cells. While there have been a few attempts to study the three-dimensional dynamics of these processes, most studies have focused on the dynamics extracted from single focal planes. However, the relation between the dynamics and three-dimensional cell shape remains elusive, due to the lack of signaling information about the unobserved part of the Membrane. Here we show that PtdInsP3 wave dynamics are directly regulated by the three-dimensional geometry - size and shape - of the plasma Membrane. By introducing an analysis method that extracts the three-dimensional spatiotemporal activities on the entire cell Membrane, we show that PtdInsP3 waves self- regulate their dynamics within the confined Membrane area. This leads to changes in speed, orientation and pattern evolution, following the underlying excitability of the signal transduction system. Our findings emphasize the role of the plasma Membrane topology in reaction-diffusion driven biological systems and indicate its importance in other mammalian systems.
Tatsuo Shibata - One of the best experts on this subject based on the ideXlab platform.
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three dimensional cell geometry controls Excitable Membrane signaling in dictyostelium cells
Biophysical Journal, 2019Co-Authors: Marcel Horning, Tatsuo ShibataAbstract:Abstract Phosphatidylinositol (3–5)-trisphosphate (PtdInsP3) is known to propagate as waves on the plasma Membrane and is related to the Membrane-protrusive activities in Dictyostelium and mammalian cells. Although there have been a few attempts to study the three-dimensional (3D) dynamics of these processes, most studies have focused on the dynamics extracted from single focal planes. However, the relation between the dynamics and 3D cell shape remains elusive because of the lack of signaling information about the unobserved part of the Membrane. Here, we show that PtdInsP3 wave dynamics are directly regulated by the 3D geometry (i.e., size and shape) of the plasma Membrane. By introducing an analysis method that extracts the 3D spatiotemporal activities on the entire cell Membrane, we show that PtdInsP3 waves self-regulate their dynamics within the confined Membrane area. This leads to changes in speed, orientation, and pattern evolution, following the underlying excitability of the signal transduction system. Our findings emphasize the role of the plasma Membrane topology in reaction-diffusion-driven biological systems and indicate its importance in other mammalian systems.
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three dimensional cell geometry controls Excitable Membrane signaling in dictyotelium cells
bioRxiv, 2018Co-Authors: Marcel Horning, Tatsuo ShibataAbstract:Phosphatidylinositol (3,4,5)-trisphosphate (PtdInsP3) is known to propagate as waves on the plasma Membrane and is related to the Membrane protrusive activities in Dictyostelium and mammalian cells. While there have been a few attempts to study the three-dimensional dynamics of these processes, most studies have focused on the dynamics extracted from single focal planes. However, the relation between the dynamics and three-dimensional cell shape remains elusive, due to the lack of signaling information about the unobserved part of the Membrane. Here we show that PtdInsP3 wave dynamics are directly regulated by the three-dimensional geometry - size and shape - of the plasma Membrane. By introducing an analysis method that extracts the three-dimensional spatiotemporal activities on the entire cell Membrane, we show that PtdInsP3 waves self- regulate their dynamics within the confined Membrane area. This leads to changes in speed, orientation and pattern evolution, following the underlying excitability of the signal transduction system. Our findings emphasize the role of the plasma Membrane topology in reaction-diffusion driven biological systems and indicate its importance in other mammalian systems.
Matthew N Rasband - One of the best experts on this subject based on the ideXlab platform.
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composition assembly and maintenance of Excitable Membrane domains in myelinated axons
Seminars in Cell & Developmental Biology, 2011Co-Authors: Matthew N RasbandAbstract:Neurons have many specialized Membrane domains with diverse functions responsible for receiving, integrating, and transmitting electrical signals between cells in a circuit. Both the locations and protein compositions of these domains defines their functions. In axons, two of the most important Membrane domains are the axon initial segment and the nodes of Ranvier. Proper assembly and maintenance of these domains is necessary for action potential generation and propagation, and the overall function of the neuron.
Peter Hänggi - One of the best experts on this subject based on the ideXlab platform.
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Intrinsic coherence resonance in Excitable Membrane patches
Mathematical Biosciences, 2007Co-Authors: Gerhard Schmid, Peter HänggiAbstract:The influence of intrinsic channel noise on the spiking activity of Excitable Membrane patches is studied by use of a stochastic generalization of the Hodgkin-Huxley model. Internal noise stemming from the stochastic dynamics of individual ion channels does affect the electric properties of the cell-Membrane patches. There exists an optimal size of the Membrane patch for which the internal noise alone can cause a nearly regular spontaneous generation of action potentials. We consider the influence of intrinsic channel noise in presence of a constant and an oscillatory current driving for both, the mean interspike interval and the phenomenon of coherence resonance for neuronal spiking. Given small Membrane patches, implying that channel noise dominates the Excitable dynamics, we find the phenomenon of intrinsic coherence resonance. In this case, the relatively regular spiking behavior becomes essentially independent of an applied stimulus. We observed, however, the occurrence of a skipping of supra-threshold input events due to channel noise for intermediate patch sizes. This effect consequently reduces the overall coherence of the spiking.
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Controlling the spiking activity in Excitable Membranes via poisoning
Physica A-statistical Mechanics and Its Applications, 2004Co-Authors: Gerhard Schmid, Igor Goychuk, Peter HänggiAbstract:The influence of intrinsic channel noise on the spontaneous spiking activity of poisoned Excitable Membrane patches is studied by use of a stochastic generalization of the Hodgkin–Huxley model. Internal noise stemming from the stochastic dynamics of individual ion channels is known to affect the collective properties of the whole ion channel cluster. There exists an optimal size of the Membrane patch for which, solely, the internal noise causes a most regular spontaneous generation of action potentials. In addition to the variation of the size of ion channel clusters, living organisms may adopt the densities of ion channels in order to optimally regulate the spontaneous spiking activity. In our model, we selectively control via poisoning the densities of specific, active ion channels. Interestingly enough, by such poisoning of some of the potassium, or the sodium ion channels, respectively, it is possible to either increase, or decrease the regularity of the spike train.
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Channel noise and synchronization in Excitable Membranes
Physica A-statistical Mechanics and Its Applications, 2003Co-Authors: Gerhard Schmid, Igor Goychuk, Peter HänggiAbstract:Using a stochastic generalization of the Hodgkin–Huxley model, we consider the influence of intrinsic channel noise on the synchronization between the spiking activity of the Excitable Membrane and an externally applied periodic signal. For small patches, i.e., when the channel noise dominates the Excitable dynamics, we find the phenomenon of intrinsic coherence resonance. In this case, the relatively regular spiking behavior is practically independent of the applied external driving; therefore no synchronization occurs. Synchronization takes place, however, only for sufficiently large ion channel assemblies. The neuronal signal processing is thus likely rooted in the collective properties of optimally large assemblies of ion channels.
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Channel noise and synchronization in Excitable Membranes
Physica A: Statistical Mechanics and its Applications, 2003Co-Authors: Gerhard Schmid, Igor Goychuk, Peter HänggiAbstract:Using a stochastic generalization of the Hodgkin–Huxley model, we consider the influence of intrinsic channel noise on the synchronization between the spiking activity of the Excitable Membrane and an externally applied periodic signal. For small patches, i.e., when the channel noise dominates the Excitable dynamics, we find the phenomenon of intrinsic coherence resonance. In this case, the relatively regular spiking behavior is practically independent of the applied external driving; therefore no synchronization occurs. Synchronization takes place, however, only for sufficiently large ion channel assemblies. The neuronal signal processing is thus likely rooted in the collective properties of optimally large assemblies of ion channels.Comment: 12 pages, 5 figures, published 200
