Medial Superior Olivary Nucleus


The medial superior olivary nucleus was present as a column of neurons.  

For instance, both convulsing agents decreased the amplitude and increased the latency of P4, that is the wave component of the ABRs generated in the lateral superior olivary nucleus and while PTZ increased the latency of P3, the wave component of the ABRs generated in the medial superior olivary nucleus, 4-AP dramatically increased its amplitude.  

The medial superior olivary nucleus is formed by a sheet of parallel-oriented cells.  

Concerning MOC neurons, we confirm and extend previous observations on the clustering of these neurons near the rostral tip of the medial superior olivary nucleus and also show that MOC neurons differ in size according to cell group.  

Optical density (OD) measurements were made from individual neurons in the anteroventral cochlear nucleus (AVCN) and from medial and lateral dendritic fields in the medial superior olivary nucleus (MSO), the lateral superior olivary nucleus, and the inferior colliculus.  

We used whole cell voltage clamp recordings from neurones in rat auditory brainstem slices to study the Ca(2+) channel types involved in triggering synaptic glutamate and glycine release in the medial superior olivary nucleus.  

Local collateral projections from the medial superior olivary nucleus in the gerbil auditory brainstem were examined to study the possible communication of this nucleus with periolivary cell groups.  

But whereas GAP-43 mRNA is almost entirely lost in most of these nuclei in the adult animal, significant levels of this molecule are retained in the inferior colliculus and, most notably, in the lateral and medial superior olivary nucleus.  

In accordance with the literature, we observed neurons innervating the IC located in the lateral superior olivary nucleus (LSO) and dorsal periolivary groups (DPO) on both sides, in the superior paraolivary nucleus (SPO) predominantly ipsilateral, as well as in the ipsilateral medial superior olivary nucleus (MSO) and the medial nucleus of the trapezoid body (MNTB).  

In the auditory brainstem, this expectation has been confirmed in neurons of the medial superior olivary nucleus (MSO).  

The immunostaining in the medial and lateral superior olivary nuclei was observed as perineuronal nets around large principal neurons at the light-microscopic level, while no immunostaining was observed in the upper segment of the medial superior olivary nucleus and the medial segment of the lateral superior olivary nucleus, in which medium-sized and small neurons were located.  

The majority of cells in the medial nucleus of the trapezoid body (MNTB) showed a prominent innervation by nerve terminals that stained positive for somatostatin only whereas the medial superior olivary nucleus (MSO) was devoid of label for both peptides.  

The degree of transneuronal atrophy was determined by measuring cell size at three levels of the brain stem auditory pathway (anteroventral cochlear nucleus, medial superior olivary nucleus, and inferior colliculus).  

The distribution and morphology of axons projecting from the medial superior olivary nucleus to the dorsal nucleus of the lateral lemniscus were studied in the adult cat. Injections of Phaseolus vulgaris-leucoagglutinin, biocytin, or dextran-rhodamine in the medial superior olivary nucleus labeled axons that ascended in the lateral lemniscus. The spatial relationships of axonal domains of several axons labeled from a single injection in the medial superior olivary nucleus suggest a mosaic pattern in the laminar connections with the dorsal nucleus of the lateral lemniscus..  

The most reasonable conduction velocity estimates, from 5 m/sec at 29 wk conceptional age to 20 m/sec in adults, were produced by assuming a site of generation for wave IV near the contralateral medial superior olivary nucleus.  

The development of the inferior collicular nucleus was similar to that of the ventral cochlear nucleus and the medial superior olivary nucleus..  

Cells expressing mRNA for glutamic acid decarboxylase were most prominent in the inferior colliculus, but were also present in all lower auditory brainstem nuclei, except the medial superior olivary nucleus and medial nucleus of trapezoid body.  

PTHrP gene expression was highest in the supramamillary nucleus of the hypothalamus, medial superior olivary nucleus, and in subpopulations of cells in the neostriatum, hippocampus, and cerebral cortex.  

The development of the human medial superior olivary nucleus was studied in serial sections of 10 fetuses at 12-35 weeks of gestation (WG), an infant at 2 months of age and an adult of 63 years using an electronic planimeter with a computer. Morphometric analysis suggested that the development of the human medial superior olivary nucleus accelerates between 16 and 21 WG in terms of columnar lengths and volumes, neuronal sizes and circularity ratios, while it matures gradually in terms of the amount of Nissl bodies..  

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.  

In the superior olivary complex, labelling was reduced on the side contralateral to the lesioned ear in the medial dendritic field of the medial superior olivary nucleus and in the nucleus of the trapezoid body.  

In the present study, neuron counts were done on three key nuclei of the SOC: the medial nucleus of the trapezoid body (MNTB), the lateral superior olivary nucleus (LSO), and the medial superior olivary nucleus (MSO) in groups of Fischer 344 rats aged 3, 12, 24, and 30 months.  

Dendritic morphology and development in the medial superior olivary nucleus of the ferret were studied using the Golgi method. Horizontally oriented dendrites were observed even at birth for some cells in the medial superior olivary nucleus and bipolar dendritic fields were typical of most cells by the end of the second postnatal week.  

Furthermore, in the medial superior olivary nucleus, there are 9% fewer neurons in the domestic form, but the neuron density has increased by 28%..  

In contrast, the ventrolateral EE region receives projections from the ipsilateral medial superior olivary nucleus (MSO), VNLL, and INLL.  

The representation of ipsilateral space is found in the "core" of the ICc, a subdivision defined by the terminal field of nucleus laminaris, the avian analogue of the medial superior olivary nucleus.  

We searched for such a delay line in the medial superior olivary nucleus of anesthetized cats.  

Previous reports have suggested that neurons of the medial superior olivary nucleus in albino cats and rabbits are smaller than those in normally pigmented strains. In this investigation, the mean cross-sectional areas of neuronal perikarya in the medial superior olivary nucleus of pigmented and albino ferrets were compared at juvenile (14 weeks) and adult (greater than six months) ages.  

A retrograde tracing study in the mole using wheat germ-agglutinated horseradish peroxidase (WGA-HRP) indicated that the medial superior olivary nucleus (MSO) projects to the inferior colliculus (IC) bilaterally.  

The right medial superior olivary nucleus, medial nucleus of the trapezoid body, lateral lemniscus nucleus, inferior colliculus, medial geniculate body, and auditory cortex had 5 to 9% less incorporation than did corresponding left-side regions.  

The greatest number of labelled neurons was found in the cochlear nuclei contralateral to the injection site, the ipsilateral medial superior olivary nucleus, both lateral superior olivary nuclei, the ipsilateral ventral nucleus of the lateral lemniscus, both dorsal nuclei of the lateral lemniscus, and the contralateral inferior colliculus.  

DYN B cell bodies were present in nonpyramidal cells of neo- and allocortices, medium-sized cells of the caudate-putamen, nucleus accumbens, lateral part of the central nucleus of the amygdala, bed nucleus of the stria terminalis, preoptic area, and in sectors of nearly every hypothalamic nucleus and area, medial pretectal area, and nucleus of the optic tract, periaqueductal gray, raphe nuclei, cuneiform nucleus, sagulum, retrorubral nucleus, peripeduncular nucleus, lateral terminal nucleus, pedunculopontine nucleus, mesencephalic trigeminal nucleus, parabigeminal nucleus, dorsal nucleus of the lateral lemniscus, lateral superior olivary nucleus, superior paraolivary nucleus, medial superior olivary nucleus, ventral nucleus of the trapezoid body, lateral dorsal tegmental nucleus, accessory trigeminal nucleus, solitary nucleus, nucleus ambiguus, paratrigeminal nucleus, area postrema, lateral reticular nucleus, and ventrolateral region of the reticular formation.  

The medial superior olivary nucleus receives input only from the anterior and posterodorsal subdivisions of the anterior division of the anteroventral cochlear nucleus (AA and APD, respectively; Brawer, Morest, and Kane: J. Like the medial superior olivary nucleus, the lateral superior olivary nucleus receives inputs from AA and APD. The projections to the medial superior olivary nucleus are bilateral, whereas the projections to the lateral superior olivary nucleus are almost entirely ipsilateral. One implication of the results is that the medial superior olivary nucleus receives inputs from only one cell type--the spherical bushy cell--but that, at the least, two cell types project to the lateral superior olivary nucleus.  

Anomalies in the auditory brainstem evoked response of albino cats were correlated with anatomical defects in the medial superior olivary nucleus (MSO) of the same animals.  

Following injections of tritiated leucine into MNTB, labeled axons reached LSO by passing ventral to, dorsal to, and through the medial superior olivary nucleus, and gave rise to labeling around the somata and proximal dendrites of LSO fusiform cells.  

Likewise, after injections in the medial superior olivary nucleus anterograde label was observed in the contralateral medial and lateral superior olivary nuclei.  

Neurons in the medial superior olivary nucleus (MSO) of albinos were, on average, 41% smaller than in pigmented animals; there was no overlap in the neuronal size distributions for the two groups of animals.  

Features of the organization of the efferent axonal projections from the medial superior olivary nucleus (MSO) in the cat were studied.  

The lateral OC system has cell bodies lateral to the medial superior olivary nucleus (MSO) and projects to the inner hair cell (IHC) region bilaterally (mostly ipsilaterally).  

Nucleus magnocellularis and nucleus laminaris in the avian brainstem contain second- and third-order auditory neurons thought to be homologous to the mammalian anteroventral cochlear nucleus and medial superior olivary nucleus, respectively.  

Right and left sides were not significantly different (P greater than 0.05) for the following neuronal types: fusiform cells and coarse- and fine-Nissl deep cells of the dorsal cochlear nucleus, and rostral bipolar cells of the medial superior olivary nucleus.  

Dendritic arborization pattern, spatial and synaptic relations of various neuron types and the terminal distribution of afferent axons of various origin were studied in the medial superior olivary nucleus of the cat using Golgi, degeneration, electron microscope and horseradish peroxidase techniques.  

In addition, cells and axons in nucleus laminaris, the presumed homologue of the mammalian medial superior olivary nucleus, are also described.  

Correlated studies of the ear and brainstem in deaf and hearing white cats have demonstrated early and progressive changes both peripherally and centrally, including organ of Corti degeneration, loss of spiral ganglion cells and auditory nerve fibers and decrease of neuronal size in the medial superior olivary nucleus (MSO).  

This holds also for the organization of the superior olivary complex where a well-developed medial superior olivary nucleus was found.  

Binaural response properties of single neurons in the medial superior olivary nucleus (MSO) were investigated in the anesthetized rat.  

In the lateral trapezoid nucleus peak production time is day E12; in the medial superior olivary nucleus, day E13; in the medial trapezoid nucleus, day E15; and in the lateral superior olivary nucleus, day E16.  

Electron microscopic analysis of the perikaryal surfaces of central and marginal cells in the cat medial superior olivary nucleus has revealed three differences in their relationships with synaptic terminals.  

Virtually all neurons of the ventral nucleus of the lateral lemniscus and the medial superior olivary nucleus ipsilateral to the injection side appear to project to the IC.  

Labeled axons entering the trapezoid body (TB) projected ipsilaterally to: (1) the lateral trapezoid nuclei (LTN), (2) the lateral superior olivary nucleus (LSO), (3) the dorsal dendritic zone of the medial superior olivary nucleus (MSO), and (4) the pericollicular or cortical nucleus of the inferior colliculus (IC).  

The medial superior olivary nucleus (MSO) has a strictly ipsilateral projection, whilst LSO projects symmetrically through the lateral lemniscus (LL) of both sides, to end with topically arranged terminals in the ventrolateral part of the central nucleus of the inferior colliculus (CNIC).  

HRP-positive cells were found in ipsilateral and contralateral lateral superior olivary nucleus (LSO), ipsilateral medial superior olivary nucleus (MSO), ipsilateral and contralateral lateral nucleus of the trapezoid body (LTB), ipsilateral ventral nucleus of the trapezoid body (VTB), and ipsilateral superior paraolivary nucleus (SPN).  

The result of this calculation is the firing probability of the primary detector (the neuron of the medial superior olivary nucleus).  

The processes in perceptors, the neurons of spiral ganglion, anterior ventral cochlear nucleus and medial superior olivary nucleus are simulated.  

The morphology and distribution of axon terminals on central column and marginal neurons of the cat medial superior olivary nucleus (MSO) were analyzed by electron microscopy.  


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