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Bob Jacobs - One of the best experts on this subject based on the ideXlab platform.

  • the neocortex of cetartiodactyls i a comparative golgi analysis of neuronal morphology in the bottlenose dolphin tursiops truncatus the minke whale balaenoptera acutorostrata and the humpback whale megaptera novaeangliae
    Brain Structure & Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin (Tursiops truncatus), the North Atlantic minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae). Golgi-stained neurons (n = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin < minke whale < humpback whale). The present data thus suggest that certain spiny neuron morphologies may be apomorphies in the neocortex of cetaceans as compared to other mammals and that neuronal dendritic extent covaries with brain and body size.

  • The neocortex of cetartiodactyls: I. A comparative Golgi analysis of neuronal morphology in the bottlenose dolphin (Tursiops truncatus), the minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae)
    Brain Structure and Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin ( Tursiops truncatus ), the North Atlantic minke whale ( Balaenoptera acutorostrata ), and the humpback whale ( Megaptera novaeangliae ). Golgi-stained neurons ( n  = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin 

Camilla Butti - One of the best experts on this subject based on the ideXlab platform.

  • the neocortex of cetartiodactyls i a comparative golgi analysis of neuronal morphology in the bottlenose dolphin tursiops truncatus the minke whale balaenoptera acutorostrata and the humpback whale megaptera novaeangliae
    Brain Structure & Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin (Tursiops truncatus), the North Atlantic minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae). Golgi-stained neurons (n = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin < minke whale < humpback whale). The present data thus suggest that certain spiny neuron morphologies may be apomorphies in the neocortex of cetaceans as compared to other mammals and that neuronal dendritic extent covaries with brain and body size.

  • The neocortex of cetartiodactyls: I. A comparative Golgi analysis of neuronal morphology in the bottlenose dolphin (Tursiops truncatus), the minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae)
    Brain Structure and Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin ( Tursiops truncatus ), the North Atlantic minke whale ( Balaenoptera acutorostrata ), and the humpback whale ( Megaptera novaeangliae ). Golgi-stained neurons ( n  = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin 

David Laberge - One of the best experts on this subject based on the ideXlab platform.

  • Neuroelectric Tuning of Cortical Oscillations by Apical Dendrites in Loop Circuits.
    Frontiers in systems neuroscience, 2017
    Co-Authors: David Laberge, Ray S. Kasevich
    Abstract:

    Clusters of relatively long Apical Dendrites dominate the neurons that make up the thickness of the cerebral cortex. It is proposed that a major function of the Apical Dendrite is to produce sustained oscillations at a specific frequency that can serve as a common timing unit for the processing of information in circuits connected to that Apical Dendrite. Many layer 5 and 6 pyramidal neurons are connected to thalamic neurons in loop circuits. A model of the Apical Dendrites of these pyramidal neurons has been used to simulate the electric activity of the Apical Dendrite. The results of that simulation demonstrated that subcortical electric pulses in these Apical Dendrites can be tuned to specific frequencies and also can be fine-tuned to narrow bandwidths of less than one Hertz (1 Hz). Synchronous pulse outputs from the circuit loops containing Apical Dendrites can tune subthreshold membrane oscillations of neurons they contact. When the pulse outputs are finely-tuned, they function as a local “clock,” which enables the contacted neurons to synchronously communicate with each other. Thus, a shared tuning frequency can select neurons for membership in a circuit. Unlike layer 6 Apical Dendrites, layer 5 Apical Dendrites can produce burst firing in many of their neurons, which increases the amplitude of signals in the neurons they contact. This difference in amplitude of signals serves as basis of selecting a sub-circuit for specialized processing (e.g., sustained attention) within the typically larger layer 6-based circuit. After examining the sustaining of oscillations in loop circuits and the processing of spikes in network circuits, we propose that cortical functioning can be globally viewed as two systems: a loop system and a network system. The loop system oscillations influence the network system’s pulse timing and the amplitude of signals, both of which affect the selection of circuits that are momentarily dominant in cortical activity.

  • Neuroelectric Tuning of Cortical Oscillations by Apical Dendrites in Loop Circuits
    Frontiers Media S.A., 2017
    Co-Authors: David Laberge, Ray S. Kasevich
    Abstract:

    Bundles of relatively long Apical Dendrites dominate the neurons that make up the thickness of the cerebral cortex. It is proposed that a major function of the Apical Dendrite is to produce sustained oscillations at a specific frequency that can serve as a common timing unit for the processing of information in circuits connected to that Apical Dendrite. Many layer 5 and 6 pyramidal neurons are connected to thalamic neurons in loop circuits. A model of the Apical Dendrites of these pyramidal neurons has been used to simulate the electric activity of the Apical Dendrite. The results of that simulation demonstrated that subthreshold electric pulses in these Apical Dendrites can be tuned to specific frequencies and also can be fine-tuned to narrow bandwidths of less than one Hertz (1 Hz). Synchronous pulse outputs from the circuit loops containing Apical Dendrites can tune subthreshold membrane oscillations of neurons they contact. When the pulse outputs are finely tuned, they function as a local “clock,” which enables the contacted neurons to synchronously communicate with each other. Thus, a shared tuning frequency can select neurons for membership in a circuit. Unlike layer 6 Apical Dendrites, layer 5 Apical Dendrites can produce burst firing in many of their neurons, which increases the amplitude of signals in the neurons they contact. This difference in amplitude of signals serves as basis of selecting a sub-circuit for specialized processing (e.g., sustained attention) within the typically larger layer 6-based circuit. After examining the sustaining of oscillations in loop circuits and the processing of spikes in network circuits, we propose that cortical functioning can be globally viewed as two systems: a loop system and a network system. The loop system oscillations influence the network system’s timing and amplitude of pulse signals, both of which can select circuits that are momentarily dominant in cortical activity

  • Cortical minicolumn and corticothalamic circuit.
    2013
    Co-Authors: Ray S. Kasevich, David Laberge
    Abstract:

    (A) Schematic diagram of a minicolumn in monkey visual cortex (see Figure 19 in [46]). Shown are somas and Apical Dendrites of pyramidal neurons and somas of stellate neurons. (B) Schematic diagram showing the corticothalamic loop. A specific resonance profile in a Layer 5 Apical Dendrite is projected, via the thalamus, back to the first compartment of the same Apical Dendrite. The profile is also projected to Apical Dendrites of Layer 2/3 pyramidal neurons where it spreads to the basal Dendrites and may influence the selection of inputs arriving from other cortical minicolumns. For clarity, the reticular nucleus, with its inhibitory projections to the thalamic principal neurons, is not shown. Adapted from [30], [31].

  • Theory of electric resonance in the neocortical Apical Dendrite.
    PloS one, 2011
    Co-Authors: Ray S. Kasevich, David Laberge
    Abstract:

    Pyramidal neurons of the neocortex display a wide range of synchronous EEG rhythms, which arise from electric activity along the Apical Dendrites of neocortical pyramidal neurons. Here we present a theoretical description of oscillation frequency profiles along Apical Dendrites which exhibit resonance frequencies in the range of 10 to 100 Hz. The Apical Dendrite is modeled as a leaky coaxial cable coated with a dielectric, in which a series of compartments act as coupled electric circuits that gradually narrow the resonance profile. The tuning of the peak frequency is assumed to be controlled by the average amplitude of voltage-gated outward currents, which in turn are regulated by the subthreshold noise in the thousands of synaptic spines that are continuously bombarded by local circuits. The results of simulations confirmed the ability of the model both to tune the peak frequency in the 10–100 Hz range and to gradually narrow the resonance profile. Considerable additional narrowing of the resonance profile is provided by repeated looping through the Apical Dendrite via the corticothalamocortical circuit, which reduced the width of each resonance curve (at half-maximum) to approximately 1 Hz. Synaptic noise in the neural circuit is discussed in relation to the ways it can influence the narrowing process.

  • Theory of Electric Resonance in the Neocortical Apical Dendrite - eScholarship
    2011
    Co-Authors: Ray S. Kasevich, David Laberge
    Abstract:

    Pyramidal neurons of the neocortex display a wide range of synchronous EEG rhythms, which arise from electric activity along the Apical Dendrites of neocortical pyramidal neurons. Here we present a theoretical description of oscillation frequency profiles along Apical Dendrites which exhibit resonance frequencies in the range of 10 to 100 Hz. The Apical Dendrite is modeled as a leaky coaxial cable coated with a dielectric, in which a series of compartments act as coupled electric circuits that gradually narrow the resonance profile. The tuning of the peak frequency is assumed to be controlled by the average amplitude of voltage-gated outward currents, which in turn are regulated by the subthreshold noise in the thousands of synaptic spines that are continuously bombarded by local circuits. The results of simulations confirmed the ability of the model both to tune the peak frequency in the 10–100 Hz range and to gradually narrow the resonance profile. Considerable additional narrowing of the resonance profile is provided by repeated looping through the Apical Dendrite via the corticothalamocortical circuit, which reduced the width of each resonance curve (at half-maximum) to approximately 1 Hz. Synaptic noise in the neural circuit is discussed in relation to the ways it can influence the narrowing process.

Sam H Ridgway - One of the best experts on this subject based on the ideXlab platform.

  • the neocortex of cetartiodactyls i a comparative golgi analysis of neuronal morphology in the bottlenose dolphin tursiops truncatus the minke whale balaenoptera acutorostrata and the humpback whale megaptera novaeangliae
    Brain Structure & Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin (Tursiops truncatus), the North Atlantic minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae). Golgi-stained neurons (n = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin < minke whale < humpback whale). The present data thus suggest that certain spiny neuron morphologies may be apomorphies in the neocortex of cetaceans as compared to other mammals and that neuronal dendritic extent covaries with brain and body size.

  • The neocortex of cetartiodactyls: I. A comparative Golgi analysis of neuronal morphology in the bottlenose dolphin (Tursiops truncatus), the minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae)
    Brain Structure and Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin ( Tursiops truncatus ), the North Atlantic minke whale ( Balaenoptera acutorostrata ), and the humpback whale ( Megaptera novaeangliae ). Golgi-stained neurons ( n  = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin 

Joy S Reidenberg - One of the best experts on this subject based on the ideXlab platform.

  • the neocortex of cetartiodactyls i a comparative golgi analysis of neuronal morphology in the bottlenose dolphin tursiops truncatus the minke whale balaenoptera acutorostrata and the humpback whale megaptera novaeangliae
    Brain Structure & Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin (Tursiops truncatus), the North Atlantic minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae). Golgi-stained neurons (n = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin < minke whale < humpback whale). The present data thus suggest that certain spiny neuron morphologies may be apomorphies in the neocortex of cetaceans as compared to other mammals and that neuronal dendritic extent covaries with brain and body size.

  • The neocortex of cetartiodactyls: I. A comparative Golgi analysis of neuronal morphology in the bottlenose dolphin (Tursiops truncatus), the minke whale (Balaenoptera acutorostrata), and the humpback whale (Megaptera novaeangliae)
    Brain Structure and Function, 2015
    Co-Authors: Camilla Butti, Caroline M Janeway, Courtney Townshend, Bridget Wicinski, Joy S Reidenberg, Sam H Ridgway, Chet C Sherwood, Patrick R Hof, Bob Jacobs
    Abstract:

    The present study documents the morphology of neurons in several regions of the neocortex from the bottlenose dolphin ( Tursiops truncatus ), the North Atlantic minke whale ( Balaenoptera acutorostrata ), and the humpback whale ( Megaptera novaeangliae ). Golgi-stained neurons ( n  = 210) were analyzed in the frontal and temporal neocortex as well as in the primary visual and primary motor areas. Qualitatively, all three species exhibited a diversity of neuronal morphologies, with spiny neurons including typical pyramidal types, similar to those observed in primates and rodents, as well as other spiny neuron types that had more variable morphology and/or orientation. Five neuron types, with a vertical Apical Dendrite, approximated the general pyramidal neuron morphology (i.e., typical pyramidal, extraverted, magnopyramidal, multiApical, and bitufted neurons), with a predominance of typical and extraverted pyramidal neurons. In what may represent a cetacean morphological apomorphy, both typical pyramidal and magnopyramidal neurons frequently exhibited a tri-tufted variant. In the humpback whale, there were also large, star-like neurons with no discernable Apical Dendrite. Aspiny bipolar and multipolar interneurons were morphologically consistent with those reported previously in other mammals. Quantitative analyses showed that neuronal size and dendritic extent increased in association with body size and brain mass (bottlenose dolphin