The Experts below are selected from a list of 156 Experts worldwide ranked by ideXlab platform

Heidegard Hilbig - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of the rhesus monkey Superior Olivary complex by calcium binding proteins and synaptophysin.
    Journal of anatomy, 2005
    Co-Authors: Ivonne Bazwinsky, Hans-jürgen Bidmon, Karl Zilles, Heidegard Hilbig
    Abstract:

    This study was performed in order to characterize the main nuclei of the rhesus monkey Superior Olivary complex by means of antibodies against the calcium binding proteins parvalbumin, calbindin and calretinin and the synaptic vesicle protein synaptophysin. These markers revealed the neuronal morphology and organization of nuclei located within the rhesus monkey Superior Olivary complex. The architectural details included the distribution of axonal terminals on neurons. The medial Superior Olivary Nucleus was present as a column of neurons. No clear segregation of calretinin-positive terminals was noticed on the medial and lateral dendritic fields of these neurons. The lateral Superior Olivary Nucleus was characterized by a distinct nuclear shape. Calretinin-, parvalbumin- or calbindin-positive terminals contacted somata and dendrites. The medial Nucleus of trapezoid body could be clearly differentiated as a distinct region in the rhesus monkey Superior Olivary complex. Somata of that Nucleus showed calbindin- and parvalbumin-labelling whereas somatic calyces of Held were reavealed by calretinin and synaptophysin labelling. The results are discussed with respect to the processing of acoustic information in primate species and their ability to hear high and low frequencies, which is reflected by anatomical correlates.

  • Characterization of the human Superior Olivary complex by calcium binding proteins and neurofilament H (SMI-32).
    The Journal of comparative neurology, 2003
    Co-Authors: Ivonne Bazwinsky, Hans-jürgen Bidmon, Heidegard Hilbig, Rudolf Rübsamen
    Abstract:

    This study provides a morphologic characterization of the human Superior Olivary complex as revealed by immunohistochemistry by using antibodies against the calcium binding proteins parvalbumin, calbindin, calretinin, and the nonphosphorylated neurofilament H SMI-32. By combining these markers, it was possible to establish the neuronal architecture and details of the morphologic organization (including axonal terminals) of the different nuclei. The medial Superior Olivary Nucleus is formed by a sheet of parallel-oriented cells. A clear segregation of axon terminals was noticed on the medially and laterally oriented dendrites of the mostly bipolar neurons. The lateral Superior Olivary Nucleus lacked a distinct nuclear shape but was formed by several patches of rather irregularly arranged neurons. Calretinin or parvalbumin immunoreactive afferent terminals were observed which contacted somata or dendrites of these neurons. The immunolabeling also revealed the boundaries of the dorsal periOlivary Nucleus and morphologic detail of its neurons. A coherent nuclear structure that could be addressed as the medial Nucleus of the trapezoid body was not identified by any single one or by combinations of the markers used. The data were also used to establish a three-dimensional-reconstruction of the three major subnuclei of the Superior Olivary complex. The results are discussed with respect to the possible role of the Superior Olivary complex in the processing of spatial acoustic information in the azimuthal plane.

Ivonne Bazwinsky - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of the rhesus monkey Superior Olivary complex by calcium binding proteins and synaptophysin.
    Journal of anatomy, 2005
    Co-Authors: Ivonne Bazwinsky, Hans-jürgen Bidmon, Karl Zilles, Heidegard Hilbig
    Abstract:

    This study was performed in order to characterize the main nuclei of the rhesus monkey Superior Olivary complex by means of antibodies against the calcium binding proteins parvalbumin, calbindin and calretinin and the synaptic vesicle protein synaptophysin. These markers revealed the neuronal morphology and organization of nuclei located within the rhesus monkey Superior Olivary complex. The architectural details included the distribution of axonal terminals on neurons. The medial Superior Olivary Nucleus was present as a column of neurons. No clear segregation of calretinin-positive terminals was noticed on the medial and lateral dendritic fields of these neurons. The lateral Superior Olivary Nucleus was characterized by a distinct nuclear shape. Calretinin-, parvalbumin- or calbindin-positive terminals contacted somata and dendrites. The medial Nucleus of trapezoid body could be clearly differentiated as a distinct region in the rhesus monkey Superior Olivary complex. Somata of that Nucleus showed calbindin- and parvalbumin-labelling whereas somatic calyces of Held were reavealed by calretinin and synaptophysin labelling. The results are discussed with respect to the processing of acoustic information in primate species and their ability to hear high and low frequencies, which is reflected by anatomical correlates.

  • Characterization of the human Superior Olivary complex by calcium binding proteins and neurofilament H (SMI-32).
    The Journal of comparative neurology, 2003
    Co-Authors: Ivonne Bazwinsky, Hans-jürgen Bidmon, Heidegard Hilbig, Rudolf Rübsamen
    Abstract:

    This study provides a morphologic characterization of the human Superior Olivary complex as revealed by immunohistochemistry by using antibodies against the calcium binding proteins parvalbumin, calbindin, calretinin, and the nonphosphorylated neurofilament H SMI-32. By combining these markers, it was possible to establish the neuronal architecture and details of the morphologic organization (including axonal terminals) of the different nuclei. The medial Superior Olivary Nucleus is formed by a sheet of parallel-oriented cells. A clear segregation of axon terminals was noticed on the medially and laterally oriented dendrites of the mostly bipolar neurons. The lateral Superior Olivary Nucleus lacked a distinct nuclear shape but was formed by several patches of rather irregularly arranged neurons. Calretinin or parvalbumin immunoreactive afferent terminals were observed which contacted somata or dendrites of these neurons. The immunolabeling also revealed the boundaries of the dorsal periOlivary Nucleus and morphologic detail of its neurons. A coherent nuclear structure that could be addressed as the medial Nucleus of the trapezoid body was not identified by any single one or by combinations of the markers used. The data were also used to establish a three-dimensional-reconstruction of the three major subnuclei of the Superior Olivary complex. The results are discussed with respect to the possible role of the Superior Olivary complex in the processing of spatial acoustic information in the azimuthal plane.

Richard L Hyson - One of the best experts on this subject based on the ideXlab platform.

  • projections from the lateral Nucleus of the trapezoid body to the medial Superior Olivary Nucleus in the gerbil
    Hearing Research, 1992
    Co-Authors: Nell B Cant, Richard L Hyson
    Abstract:

    Abstract We made small injections of horseradish peroxidase into the medial Superior Olivary Nucleus (MSO) of gerbils in order to examine the sources of input into that Nucleus. As previously described, the MSO receives inputs from neurons in the rostral part of both anteroventral cochlear nuclei. In addition, we found evidence for a projection from the ipsilateral lateral Nucleus of the trapezoid body (LNTB). Our results are also compatible with previous reports that the medial Nucleus of the trapezoid body (MNTB) projects to the MSO. It is likely that these projections into the MSO from the LNTB and MNTB are sources of inhibitory synaptic inputs.

Edwin W. Rubel - One of the best experts on this subject based on the ideXlab platform.

  • Tonotopic organization of the Superior Olivary Nucleus in the chicken auditory brainstem
    The Journal of comparative neurology, 2012
    Co-Authors: Kathryn M. Tabor, Edwin W. Rubel, William L. Coleman, R. Michael Burger
    Abstract:

    Topographic maps are salient features of neuronal organization in sensory systems. Inhibitory components of neuronal circuitry are often embedded within this organization, making them difficult to isolate experimentally. The auditory system provides opportunities to study the topographic organization of inhibitory long-range projection nuclei, such as the Superior Olivary Nucleus (SON). We analyzed the topographic organization of response features of neurons in the SON of chickens. Quantitative methods were developed to assess and communicate this organization. These analyses led to three main conclusions: 1) sound frequency is linearly arranged from dorsal (low frequencies) to ventral (high frequencies) in SON; 2) this tonotopic organization is less precise than the organization of the excitatory nuclei in the chicken auditory brainstem; and 3) neurons with different response patterns to pure tone stimuli are interspersed throughout the SON and show similar tonotopic organizations. This work provides a predictive model to determine the optimal stimulus frequency for a neuron from its spatial location in the SON.

  • Topography and morphology of the inhibitory projection from Superior Olivary Nucleus to Nucleus laminaris in chickens (Gallus gallus).
    The Journal of comparative neurology, 2010
    Co-Authors: Kathryn M. Tabor, Rachel O.l. Wong, Edwin W. Rubel
    Abstract:

    The avian Nucleus laminaris (NL) is involved in computation of interaural time differences (ITDs) that encode the azimuthal position of a sound source. Neurons in NL are bipolar, with dorsal and ventral dendritic arbors receiving input from separate ears. NL neurons act as coincidence detectors that respond maximally when input from each ear arrives at the two dendritic arbors simultaneously. Computational and physiological studies demonstrated that the sensitivity of NL neurons to coincident inputs is modulated by an inhibitory feedback circuit via the Superior Olivary Nucleus (SON). To understand the mechanism of this modulation, the topography of the projection from SON to NL was mapped, and the morphology of the axon terminals of SON neurons in NL was examined in chickens (Gallus gallus). In vivo injection of AlexaFluor 568 dextran amine into SON demonstrated a coarse topographic projection from SON to NL. Retrogradely labeled neurons in NL were located within the zone of anterogradely labeled terminals, suggesting a reciprocal projection from SON to NL. In vivo extracellular physiological recording further demonstrated that this topography is consistent with tonotopic maps in SON and NL. In addition, three-dimensional reconstruction of single SON axon branches within NL revealed that individual SON neurons innervate a large area of NL and terminate on both dorsal and ventral dendritic arbors of NL neurons. The organization of the projection from SON to NL supports its proposed functions of controlling the overall activity level of NL and enhancing the specificity of frequency mapping and ITD detection.

  • Avian Superior Olivary Nucleus provides divergent inhibitory input to parallel auditory pathways.
    The Journal of comparative neurology, 2005
    Co-Authors: R. Michael Burger, Karina S. Cramer, Joshua D. Pfeiffer, Edwin W. Rubel
    Abstract:

    The avian auditory brainstem displays parallel processing, a fundamental feature of vertebrate sensory systems. Nuclei specialized for temporal processing are largely separate from those processing other aspects of sound. One possible exception to this parallel organi- zation is the inhibitory input provided by the Superior Olivary Nucleus (SON) to Nucleus angularis (NA), Nucleus magnocellularis (NM), and Nucleus laminaris (NL) and contralateral SON (SONc). We sought to determine whether single SON neurons project to multiple targets or separate neuronal populations project independently to individual target nuclei. We introduced two different fluorescent tracer molecules into pairs of target nuclei and quanti- fied the extent to which retrogradely labeled SON neurons were double labeled. A large proportion of double-labeled SON somata were observed in all cases in which injections were made into any pair of ipsilateral targets (NA and NM, NA and NL, or NM and NL), suggesting that many individual SON neurons project to multiple targets. In contrast, when injections involved the SONc and any or all of the ipsilateral targets, double labeling was rare, suggesting that contralateral and ipsilateral targets are innervated by distinct popu- lations of SON neurons arising largely from regionally segregated areas of SON. Therefore, at the earliest stages of auditory processing, there is interaction between pathways special- ized to process temporal cues and those that process other acoustic features. We present a conceptual model that incorporates these results and suggest that SON circuitry, in part, functions to offset interaural intensity differences in interaural time difference processing.

  • The Superior Olivary Nucleus and Its Influence on Nucleus Laminaris: A Source of Inhibitory Feedback for Coincidence Detection in the Avian Auditory Brainstem
    The Journal of neuroscience : the official journal of the Society for Neuroscience, 1999
    Co-Authors: Lichuan Yang, Pablo Monsivais, Edwin W. Rubel
    Abstract:

    Located in the ventrolateral region of the avian brainstem, the Superior Olivary Nucleus (SON) receives inputs from Nucleus angularis (NA) and Nucleus laminaris (NL) and projects back to NA, NL, and Nucleus magnocellularis (NM). The reciprocal connections between the SON and NL are of particular interest because they constitute a feedback circuit for coincidence detection. In the present study, the chick SON was investigated. In vivo tracing studies show that the SON projects predominantly to the ipsilateral NM, NL, and NA. In vitro whole-cell recording reveals single-cell morphology, firing properties, and postsynaptic responses. SON neurons are morphologically and physiologically suited for temporal integration; their firing patterns do not reflect the temporal structure of their excitatory inputs. Of most interest, direct stimulation of the SON evokes long-lasting inhibition in NL neurons. The inhibition blocks both intrinsic spike generation and orthodromically evoked activity in NL neurons and can be eliminated by bicuculline methiodide, a potent antagonist for GABA A receptor-mediated neurotransmission. These results strongly suggest that the SON provides GABAergic inhibitory feedback to laminaris neurons. We discuss a mechanism whereby SON-evoked GABAergic inhibition can influence the coding of interaural time differences for sound localization in the avian auditory brainstem.

  • GABAergic terminals in Nucleus magnocellularis and laminaris originate from the Superior Olivary Nucleus.
    The Journal of comparative neurology, 1994
    Co-Authors: E. A. Lachica, Rudolf Rübsamen, Edwin W. Rubel
    Abstract:

    The auditory brainstem nuclei, angularis (NA), magnocellularis (NM), and laminaris (NL) of the chicken, Gallus, contain terminals that stain for antibodies against the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA). Some of these terminals originate from cells surrounding Nucleus magnocellularis. Results from this study indicate that the majority of the GABAergic terminals found in NA, NM and NL originate from the Superior Olivary Nucleus (SON). Injections of cholera toxin and horseradish peroxidase show that Superior Olivary Nucleus (SON) neurons, which respond to pure tones, project bilaterally to NA, NM, and NL. NA and NL are reciprocally connected with the SON. More NA cells project to the SON than NL cells. While SON neurons project to NM, NM neurons do not project axons back to the SON. The configuration of SON terminals in NA, NM and NL matches the pattern of GABA-immunoreactive puncta seen in these three nuclei: they surround individual NM cells, congregate in the dendritic neuropil of NL, and blanket the NA. The data indicate that NA, NM and NL may be affected by two different inhibitory cell types: local interneurons and SON neurons. Patterns of connectivity described in this report suggest that the activity of NA cells could influence NM and NL cell physiology. Specifically, increases in NA cell activity could augment the effects of GABAergic SON neurons on NM and NL. Hence, binaural perception in the chicken may be more dependent upon changes in intensity cues than previously believed.

Hans-jürgen Bidmon - One of the best experts on this subject based on the ideXlab platform.

  • Characterization of the rhesus monkey Superior Olivary complex by calcium binding proteins and synaptophysin.
    Journal of anatomy, 2005
    Co-Authors: Ivonne Bazwinsky, Hans-jürgen Bidmon, Karl Zilles, Heidegard Hilbig
    Abstract:

    This study was performed in order to characterize the main nuclei of the rhesus monkey Superior Olivary complex by means of antibodies against the calcium binding proteins parvalbumin, calbindin and calretinin and the synaptic vesicle protein synaptophysin. These markers revealed the neuronal morphology and organization of nuclei located within the rhesus monkey Superior Olivary complex. The architectural details included the distribution of axonal terminals on neurons. The medial Superior Olivary Nucleus was present as a column of neurons. No clear segregation of calretinin-positive terminals was noticed on the medial and lateral dendritic fields of these neurons. The lateral Superior Olivary Nucleus was characterized by a distinct nuclear shape. Calretinin-, parvalbumin- or calbindin-positive terminals contacted somata and dendrites. The medial Nucleus of trapezoid body could be clearly differentiated as a distinct region in the rhesus monkey Superior Olivary complex. Somata of that Nucleus showed calbindin- and parvalbumin-labelling whereas somatic calyces of Held were reavealed by calretinin and synaptophysin labelling. The results are discussed with respect to the processing of acoustic information in primate species and their ability to hear high and low frequencies, which is reflected by anatomical correlates.

  • Characterization of the human Superior Olivary complex by calcium binding proteins and neurofilament H (SMI-32).
    The Journal of comparative neurology, 2003
    Co-Authors: Ivonne Bazwinsky, Hans-jürgen Bidmon, Heidegard Hilbig, Rudolf Rübsamen
    Abstract:

    This study provides a morphologic characterization of the human Superior Olivary complex as revealed by immunohistochemistry by using antibodies against the calcium binding proteins parvalbumin, calbindin, calretinin, and the nonphosphorylated neurofilament H SMI-32. By combining these markers, it was possible to establish the neuronal architecture and details of the morphologic organization (including axonal terminals) of the different nuclei. The medial Superior Olivary Nucleus is formed by a sheet of parallel-oriented cells. A clear segregation of axon terminals was noticed on the medially and laterally oriented dendrites of the mostly bipolar neurons. The lateral Superior Olivary Nucleus lacked a distinct nuclear shape but was formed by several patches of rather irregularly arranged neurons. Calretinin or parvalbumin immunoreactive afferent terminals were observed which contacted somata or dendrites of these neurons. The immunolabeling also revealed the boundaries of the dorsal periOlivary Nucleus and morphologic detail of its neurons. A coherent nuclear structure that could be addressed as the medial Nucleus of the trapezoid body was not identified by any single one or by combinations of the markers used. The data were also used to establish a three-dimensional-reconstruction of the three major subnuclei of the Superior Olivary complex. The results are discussed with respect to the possible role of the Superior Olivary complex in the processing of spatial acoustic information in the azimuthal plane.