Using a microchemical approach, we measured changes of amino acid concentrations in the chinchilla caudal Posteroventral Cochlear Nucleus (PVCN) after cochlear ablation to determine to what extent slow decreases of glutamate and aspartate concentrations after carboplatin treatment resulted from slower effects of cochlear damage in chinchillas than in rats and guinea pigs, as opposed to effects of carboplatin treatment being slower than those of cochlear ablation. 
The morphology of this type of synapse, and the moderate sizes of the swellings forming it, suggests that it originates from Posteroventral Cochlear Nucleus stellate/multipolar neurons.
In caudal Posteroventral Cochlear Nucleus (PVCN), the aspartate concentration decreased by 32% at 29 days, in animals with significant inner hair cell loss, and 48% at 85 days after treatment, while the glutamate concentration showed no decrease through 29 days and 40% decrease at 85 days.
Lesions involving the Posteroventral Cochlear Nucleus (PVCN), but not the other subdivisions, produced long-term decreases in MOC reflex strength.
Ventrally placed injections had an additional projection into the anteroventral cochlear nucleus, whereas dorsally placed injections had an additional projection into the Posteroventral Cochlear Nucleus.
They also provide widespread local innervation of the anteroventral cochlear nucleus and a small innervation of the Posteroventral Cochlear Nucleus.
The anterior part of the ipsilateral Posteroventral Cochlear Nucleus consistently contained a band of degenerating axons and terminals, in which electron microscopic analysis revealed substantial losses of axons and synaptic terminals with excitatory and inhibitory cytology.
Significant decreases in 2-DG uptake were found in the ipsilateral anteroventral and Posteroventral Cochlear Nucleus, with respect to the exposed left ears.
PICK1-immunoreactivity (ir) was observed in many component nuclei of the central auditory system, including the dorsal cochlear nucleus, anteroventral cochlear nucleus, Posteroventral Cochlear Nucleus, some divisions of the superior olivary complex, inferior colliculus, medial geniculate body, and primary auditory cortex.
Glutamate concentrations were 23% lower in the anteroventral cochlear nucleus (AVCN) and 40% lower in the Posteroventral Cochlear Nucleus (PVCN) of carboplatin-injected chinchillas as compared to controls, while aspartate concentrations were 18% lower in AVCN and 27% lower in PVCN.
Octopus cells in the Posteroventral Cochlear Nucleus (PVCN) of mammals are biophysically specialized to detect coincident firing in the population of auditory nerve fibers that provide their synaptic input and to convey its occurrence with temporal precision.
The quantitative stereological method, the optical fractionator, was used for determining the total number of neurons and the total number of neurons immunostained with parvalbumin, calbindin-D28k (calbindin), and calretinin in the dorsal and Posteroventral Cochlear Nucleus (DCN and PVCN) in CBA/CaJ (CBA) mice during aging (1-39 months old).
Fiber segments were most dense in the dorsal cochlear nucleus (especially in the molecular layer) and the large spherical cell area of the anteroventral cochlear nucleus; they were moderately dense in the small cell cap region; and fiber segments were least dense in the octopus and multipolar cell regions of the Posteroventral Cochlear Nucleus.
Rare labelled boutons were present on multipolar cells of type I and II, globular neurons and octopus cells in the Posteroventral Cochlear Nucleus.
The strongest GluR-C and -D flop expression is found in the ventral and medial part of the anteroventral cochlear nucleus, the Posteroventral Cochlear Nucleus, and the medial and the lateral superior olive.
Of particular interest is the octopus cell region of the Posteroventral Cochlear Nucleus (PVCN).
Octopus cells in the Posteroventral Cochlear Nucleus of mammals detect the coincidence of synchronous firing in populations of auditory nerve fibers and convey the timing of that coincidence with great temporal precision.
The changes of the cross-sectional areas of anteroventral cochlear nucleus (AVCN) and Posteroventral Cochlear Nucleus (PVCN) were studied in neonatal and adult guinea pigs after monaural cochlear ablation with computer imaging analysis system.
Enhanced temporal coding of amplitude modulation signals is found in certain dorsal and Posteroventral Cochlear Nucleus neurons when they are compared to auditory nerve. gamma-Aminobutyric acid- and glycine-mediated inhibition have been shown to shape the dorsal cochlear nucleus and Posteroventral Cochlear Nucleus response properties to other acoustic stimuli. In the present study, responses to amplitude modulation tones were obtained from chinchilla dorsal cochlear nucleus and Posteroventral Cochlear Nucleus neurons. These findings support the hypothesis that glycinergic and gamma-aminobutyric acidergic inputs onto certain dorsal cochlear nucleus and Posteroventral Cochlear Nucleus neurons play a role in shaping responses to amplitude modulation stimuli and may be responsible for the reported preservation of amplitude modulation temporal coding in dorsal cochlear nucleus and Posteroventral Cochlear Nucleus neurons at high stimulus intensities or in background noise..
The cochlear nucleus is composed of three sub-nuclei: the dorsal (DCN), anteroventral (AVCN) and Posteroventral Cochlear Nucleus (PVCN).
In anesthetized cats, stimuli were delivered to three or four locations along the dorsal-to-ventral axis of the Posteroventral Cochlear Nucleus (PVCN), and for each stimulus location, we recorded the multiunit neuronal activity and the field potentials at 20 or more locations along the dorsolateral-ventromedial (tonotopic) axis of the IC.
In the anteroventral cochlear nucleus, labelled multipolar type I and II showed similar immunocytological and ultrastructural characteristics to those in the Posteroventral Cochlear Nucleus but their dimension was smaller.
The number of calbindin D-28k and parvalbumin immunoreactive (IR) neurons were characterized on sections from the cochlear nucleus, dorsal cochlear nucleus (DCN) and Posteroventral Cochlear Nucleus (PVCN) using two-dimensional quantification.
The cochlear nucleus is composed of three sub-nuclei: the dorsal (DCN), anteroventral (AVCN) and Posteroventral Cochlear Nucleus (PVCN).
Staining of neuronal somata in the dorsal cochlear nucleus molecular layer and fusiform cell layer, the Posteroventral Cochlear Nucleus octopus cell area, and the anteroventral cochlear nucleus increased from P7 to P28. Staining of the neuropil (the unresolved mass of processes and axons, excluding only neuronal somata and distinctly stained proximal dendrites) of the deep dorsal cochlear nucleus and Posteroventral Cochlear Nucleus showed a steady decrease, while molecular layer neuropil remained moderately stained. Their stained dendrites spanned much of the dorsal cochlear nucleus deep and fusiform cell layers and even extended into the octopus cell area of the Posteroventral Cochlear Nucleus. Dendritic staining was also present in caudal and rostral Posteroventral Cochlear Nucleus, first distinguishable at P14 and becoming increasingly strong. The Chemicon polyclonal NR2B antibody produced glial staining especially prominent in the caudal Posteroventral Cochlear Nucleus and the dorsal cochlear nucleus fusiform cell layer, most intense at P7 and subsequently decreasing, although not disappearing, in all areas through P28.
Octopus cells are one of the principal cell types in the mammalian Posteroventral Cochlear Nucleus.
The anterograde tracer Phaseolus vulgaris-leucoagglutinin was used to identify the projections of the Posteroventral Cochlear Nucleus in cats. Labeled varicose fibers were also observed in regions not commonly identified as receiving input from the Posteroventral Cochlear Nucleus.
In silver impregnations of a deafferented zone in the Posteroventral Cochlear Nucleus, the concentration of axons decreased by 43% after 1 month and by 54% after 2 months.
In this study, we have characterized the phenomenon, using as the paradigm, iridium microelectrodes implanted chronically in the cat's Posteroventral Cochlear Nucleus.
The octopus cells of the Posteroventral Cochlear Nucleus receive inputs from auditory-nerve fibers and form one of the major ascending auditory pathways.
Noradrenaline (NA), dopamine (DA); serotonin (5-HT) and their metabolites-3-methoxy, 4-hydroxyphenylglycol (MHPG), 3,4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA)-were determined using HPLC in medial vestibular nucleus (MVN), anteroventral cochlear nucleus (AVCN), dorsal+Posteroventral Cochlear Nucleus (DCN+PVCN), locus coeruleus (LC) and raphe dorsalis of Dark Agouti-Hanovre (DA-HAN) rats aged 4, 21 and 24 months.
A prominent lamina of m2-immunoreactive fibers and puncta was located in a subgranular layer of the caudal anteroventral cochlear nucleus (AVCN) and the Posteroventral Cochlear Nucleus (PVCN).
(1982) proposed a primary acoustic startle circuit in rats consisting of the auditory nerve, Posteroventral Cochlear Nucleus, an area near the ventrolateral lemniscus (VLL), nucleus reticularis pontis caudalis (PnC), and spinal motoneurons.
In this study, type II axons were labeled with horseradish peroxidase, and serial-section electron microscopy was used to examine their swellings in: (1) the granule-cell lamina at its boundary with Posteroventral Cochlear Nucleus, (2) the rostral anteroventral cochlear nucleus, and (3) the auditory nerve root.
The dense FLI found in the ipsilateral dorsal cochlear nucleus, as well as the moderate FLI found in the contralateral dorsal cochlear nucleus and in the Posteroventral Cochlear Nucleus on both sides, were consistent after survival times ranging from 0 to 2-3 h, but they significantly decreased after longer survival times (5 and 6 h).
Noradrenaline (NA), dopamine (DA), serotonin (5-HT) and their metabolites, 3-methoxy,4-hydroxyphenylglycol (MHPG) and 5-hydroxyindoleacetic acid (5-HIAA), were determined using high-performance liquid chromatography with electrochemical detection in the rat anteroventral cochlear nucleus (AVCN), in the dorsal part of the nucleus including the dorsal cochlear nucleus (DCN) and the Posteroventral Cochlear Nucleus (PVCN) and as a comparison, in the locus coeruleus (LC) and dorsal raphe nucleus (RD) which contain the corresponding noradrenergic and serotonergic cell bodies.
Little binding was detected in regions of the Posteroventral Cochlear Nucleus, and no specific binding was apparent in the cerebellum.
In the Posteroventral Cochlear Nucleus, principal cells of elongate and octopus shape were observed, in contact with labeled swellings and surrounded by labeled neuropil..
Octopus cells of the Posteroventral Cochlear Nucleus form a pathway known to carry information in the timing of action potentials.
In the vicinity of the DCN/PVCN (Posteroventral Cochlear Nucleus) boundary, units were encountered that were excited by electrical stimulation in MSN; some of these neurons responded to sound, and some did not.
Although less prominent, serotonin-positive fibers were also present in the remaining part of the anteroventral cochlear nucleus and the Posteroventral Cochlear Nucleus.
After the bifurcation, the pathways of type II branches within the anteroventral cochlear nucleus (AVCN) and Posteroventral Cochlear Nucleus (PVCN) are similar to those of type I branches.
The dendritic terminals of the elongate, antenniform, and clavate cells of the Posteroventral Cochlear Nucleus link each of these cell types with neighboring structures in distinct patterns, which may provide a basis for differences in synaptic organization.
We investigated the effects of continuous microstimulation in the cats' Posteroventral Cochlear Nucleus, using chronically implanted activated iridium microelectrodes.
Cuts through the Posteroventral Cochlear Nucleus (PVCN), which severed the descending branches of auditory nerve fibers, eliminated early EPSPs and IPSPs leaving late, slowly rising EPSPs and bursts of IPSPs in responses to shocks of the auditory nerve.
Densely packed FLI neurons were widely distributed in the dorsal cochlear nucleus (more ipsilaterally than contralaterally), while FLI neurons were rare in the Posteroventral Cochlear Nucleus and virtually absent in the anteroventral cochlear nucleus.
There were statistically significant differences between stimulated and unstimulated nuclei, especially the Posteroventral Cochlear Nucleus (PVCN), in individual cats, but the directions of the differences were inconsistent.
Both excitatory and inhibitory inputs to giant cells could be driven by the local application of glutamate to many loci in the AVCN and Posteroventral Cochlear Nucleus, indicating that the ventral cochlear nucleus VCN contains interneurons that are monosynaptically or polysynaptically connected to giant cells.
There were no statistically significant difference among anteroventral cochlear nucleus (AVCN), Posteroventral Cochlear Nucleus (PVCN) and dorsal cochlear nucleus (DCN) neurons when stimulated sides were compared with unstimulated sides.
In the Posteroventral Cochlear Nucleus, another cluster of c-fos-like positive neurons was observed, whose position also varied with tones frequency.
A recent study of amplitude-modulated (AM) tone encoding behavior of dorsal and Posteroventral Cochlear Nucleus (DCN and PVCN) neurons by Kim et al.
At eight days, anti-GABA labeled cells were randomly located in the superficial and deep layer of the dorsal cochlear nucleus (DCN) in the vibratome sections, whereas they were mainly accumulated in the vicinity of the granule layer between the junction of the DCN and Posteroventral Cochlear Nucleus (PVCN) in the plastic sections.
The role of GABAergic inhibitory inputs onto Posteroventral Cochlear Nucleus (PVCN) neurons in the anesthetized chinchilla was investigated through iontophoretic application of the GABAA receptor agonist muscimol and the GABAA receptor antagonist bicuculline.
The present experiments examine the projection from the deep DCN to the Posteroventral Cochlear Nucleus (PVCN).
The efferent neural projections from Posteroventral Cochlear Nucleus to the superior olivary complex in guinea pig were examined with the Phaseolus vulgaris-leucoagglutinin anterograde tract-tracing method. Light microscopic analysis demonstrated that the Posteroventral Cochlear Nucleus of guinea pig bilaterally projects to the superior para-olivary nucleus and the rostral, medioventral, and lateroventral peri-olivary regions. Ipsilaterally, the Posteroventral Cochlear Nucleus projects to the lateral superior olive, the caudal peri-olivary region, and areas immediately surrounding the capsule of the lateral superior olive. Contralaterally, the Posteroventral Cochlear Nucleus projects to the medial nucleus of the trapezoid body. The projection pattern from Posteroventral Cochlear Nucleus was found to be topographically organized in three distinct regions. The more dorsally located neurons of the Posteroventral Cochlear Nucleus terminated dorsomedially in the ipsilateral lateral superior olive, ventromedially in the contralateral superior para-olivary nucleus, and medially in the contralateral medioventral peri-olivary region. The more ventrally located neurons of the Posteroventral Cochlear Nucleus terminated dorsolaterally in the ipsilateral lateral superior olive, dorsolaterally in the contralateral superior para-olivary nucleus, and laterally in the contralateral medioventral peri-olivary region..
Encoding of 1- and 5-kHz pure tones by auditory-nerve (AN) fibers and choppers of the Posteroventral Cochlear Nucleus (PVCN) was investigated.
The presence of ascending auditory inputs from the Posteroventral Cochlear Nucleus (PVCN) to olivocochlear neurons was examined in guinea pig by using the combination Phaseolus vulgaris-leucoagglutinin (PHA-L) anterograde and horseradish peroxidase (HRP) retrograde tract-tracing technique.
Although both Posteroventral Cochlear Nucleus (PVCN) and dorsal cochlear nucleus (DCN) are innervated by the descending branch of auditory nerve fibers, their intrinsic morphological organizations are so different that their physiological roles are expected to be different in signal processing.
Furthermore, a small number of PEP-19-positive axons of unknown origin reach the caudal rim of the Posteroventral Cochlear Nucleus.
When gerbils of various ages raised under known acoustic conditions were examined, the volume density and number of lesions increased with age, however, the affected region was restricted to the Posteroventral Cochlear Nucleus and adjacent portions of the dorsal cochlear nucleus, interstitial nucleus, and posterior anteroventral cochlear nucleus.
Type-I and type-II axons labeled by basal turn injections bifurcate together in the dorsal part of the auditory nerve root, forming a branch that ascends into the anteroventral cochlear nucleus and a branch that descends into the Posteroventral Cochlear Nucleus.
In an effort to understand what integrative tasks are performed in the cochlear nuclei, the present study was undertaken to describe neuronal circuits in the Posteroventral Cochlear Nucleus (PVCN) anatomically and physiologically.
Quantitative evaluation of tonotopy showed that the frequency representation in the anteroventral and Posteroventral Cochlear Nucleus and lateral superior olive were very similar.
Globular bushy cells are seen in the caudal region of the AVCN, but the majority occur in the Posteroventral Cochlear Nucleus (PVCN), in an area extending from the nerve root right up to the boundary of the dorsal cochlear nucleus (DCN).
We distinguish two types of large multipolar cells designated sustained (CS) and onset (OC) choppers in the anterior Posteroventral Cochlear Nucleus (A-PVCN)/nerve root region on the basis of certain anatomical and physiological features.
In young animals the microcysts were prevalent in the cochlear nerve root region and the Posteroventral Cochlear Nucleus.
Travelling close to the restiform body, the axons terminated at cells lying between the dorsal and Posteroventral Cochlear Nucleus.
In the Posteroventral Cochlear Nucleus, neurons identified as octopus cells were immunoreactive on their cell bodies and proximal dendrites.
The HRP-labeled axons travel caudally through the descending vestibular nucleus, enter the cochlear nucleus at a level caudal to subgroup y and terminate at cells situated between the dorsal and Posteroventral Cochlear Nucleus.
Neurons in category II were located in the Posteroventral Cochlear Nucleus and were presumably multipolar/stellate cells. Somata types of neurons in category III could not be identified morphologically, but somata were located in caudal parts of the Posteroventral Cochlear Nucleus that correspond to the octopus cell area.
Phaseolus vulgaris leucoagglutinin (PHA-L), a kidney bean lectin used as an anterograde tracer, was iontophoretically injected into the Posteroventral Cochlear Nucleus (PVCN) of guinea pigs.
Golgi impregnation results confirm the existence of a plexus (previously described with horseradish peroxidase tracing techniques) located in the Posteroventral Cochlear Nucleus.
The plexuses cover the posterior area of the Posteroventral Cochlear Nucleus (posterior plexus) and the anterolaterodorsal area of the anteroventral cochlear nucleus (anterior plexus).
The dorsal one-third of the central nucleus of the inferior colliculus is the principal target of the dorsal cochlear nucleus and may be a target of the Posteroventral Cochlear Nucleus.
In some cases, the collateral branches deviate from this tonotopic arrangement, particularly in (1) the octopus cell region of the Posteroventral Cochlear Nucleus, (2) the zone of bifurcations of the auditory nerve fibers, and (3) the anterior, dorsal, and lateral margins of the ventral cochlear nucleus.
In the Posteroventral Cochlear Nucleus, the "chopper" unit was a "stellate" cell and the "on" unit was an "octopus" cell.
Two cells with transient chopper response patterns were stellate cells in the Posteroventral Cochlear Nucleus with many branched and beaded dendrites.
Large, multipolar neurons in the anterior and posterior divisions of the anteroventral cochlear nucleus and in the Posteroventral Cochlear Nucleus project to the ventral and dorsal cochlear nuclei on the opposite side. In addition, giant cells in the deep layers of the dorsal cochlear nucleus project to the contralateral Posteroventral Cochlear Nucleus and possibly also to the contralateral dorsal cochlear nucleus. Although no part of the cochlear nuclear complex is completely free of anterograde label, the densest labelling is found in the anterior division of the anteroventral cochlear nucleus, throughout the Posteroventral Cochlear Nucleus (where it is closely associated with cell bodies), and in the fusiform and superficial layers of the dorsal cochlear nucleus.
Sixty-six of 282 units were localized to the Posteroventral Cochlear Nucleus, 17 from the multipolar cell area and 49 from the octopus cell area. Poststimulus time histograms revealed four response types, at the best frequency, in the Posteroventral Cochlear Nucleus.
Immunoreactivity was also seen on cells in the Posteroventral Cochlear Nucleus and in auditory nerve fibers.
The octopus cell area (OCA) of the Posteroventral Cochlear Nucleus was studied electron microscopically in kittens.
Labeled cells were abundant in the dorsal and Posteroventral Cochlear Nucleus adjacent to the injection as well as scattered throughout the periolivary cell groups of both sides, being highest in concentration around the ipsilateral lateral superior olive.
Single unit activity in the Posteroventral Cochlear Nucleus (PVCN) was recorded for a variety of stimulus conditions.
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