Neuronal architecture in nucleus magnocellularis of the chicken auditory system with observations on nucleus laminaris: A light and electron microscope study

Jhaveri, Sonal; Morest, D. Kent

doi:10.1016/0306-4522(82)90045-8

Cited by 151 publications

(101 citation statements)

References 34 publications

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“…These studies also showed a dorsoventral expression gradient that changes with development, wherein the dorsal-most areas showed early, stronger label that moved in a "front" toward the ventral pole. NM and NL are, comparatively speaking, morphologically and physiologically homogeneous nuclei with a single principal cell type (Carr and Boudreau 1993;Jhaveri and Morest 1982;Kubke and Carr 2000;MacLeod et al 2006). Calretinin was also expressed in the timing nuclei in a developmentally regulated gradient, with high/early expression levels in high-frequency (rostromedial) regions and lower/later expression in lower frequency (caudolateral) regions.…”

Section: Heterogeneity Of Calretinin Expression and Functional Diversmentioning

confidence: 99%

Heterogeneous Calretinin Expression in the Avian Cochlear Nucleus Angularis

Bloom

Williams

MacLeod

2014

JARO

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Multiple calcium-binding proteins (CaBPs) are expressed at high levels and in complementary patterns in the auditory pathways of birds, mammals, and other vertebrates, but whether specific members of the CaBP family can be used to identify neuronal subpopulations is unclear. We used double immunofluorescence labeling of calretinin (CR) in combination with neuronal markers to investigate the distribution of CR-expressing neurons in brainstem sections of the cochlear nucleus in the chicken (Gallus gallus domesticus). While CR was homogeneously expressed in cochlear nucleus magnocellularis, CR expression was highly heterogeneous in cochlear nucleus angularis (NA), a nucleus with diverse cell types analogous in function to neurons in the mammalian ventral cochlear nucleus. To quantify the distribution of CR in the total NA cell population, we used antibodies against neuronal nuclear protein (NeuN), a postmitotic neuronspecific nuclear marker. In NA neurons, NeuN label was variably localized to the cell nucleus and the cytoplasm, and the intensity of NeuN immunoreactivity was inversely correlated with the intensity of CR immunoreactivity. The percentage of CR+neurons in NA increased from 31 % in embryonic (E)17/18 chicks, to 44 % around hatching (E21), to 51 % in postnatal day (P) 8 chicks. By P8, the distribution of CR + neurons was uniform, both rostrocaudal and in the tonotopic (dorsoventral) axis.Immunoreactivity for the voltage-gated potassium ion channel Kv1.1, used as a marker for physiological type, showed broad and heterogeneous postsynaptic expression in NA, but did not correlate with CR expression. These results suggest that CR may define a subpopulation of neurons within nucleus angularis.

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Section: Heterogeneity Of Calretinin Expression and Functional Diversmentioning

confidence: 99%

Heterogeneous Calretinin Expression in the Avian Cochlear Nucleus Angularis

Bloom

Williams

MacLeod

2014

JARO

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“…The evolutionary advantages conferred by accurate timing information are embedded in sound localization acuity and auditory discrimination skills. Chick endbulbs are from Jhaveri and Morest [77,78], Plenum Press; owl endbulbs are from Carr and Boudreau [31], Wiley-Liss publishers; mouse endbulbs are from Limb and Ryugo [102], Springer publishers; cat endbulbs are from Ryugo et al [174], Wiley-Liss publishers, and Sento and Ryugo [185], Liss publishers; monkey endbulb is from Ryugo, unpublished data; human endbulb is from Adams [1], American Medical Association.…”

Section: Innervationmentioning

confidence: 99%

“…The ultrastructure of endbulbs in NM has been studied in the chick [77,138,141,142] and the barn owl [29]. The endbulbs appear most often as large elongated profiles that contain multiple sites of synaptic specialization formed directly on the cell body or on the sides of the many somatic spines; in the barn owl, 64% of the synapses are on spines.…”

Section: Fine Structurementioning

confidence: 99%

Primary innervation of the avian and mammalian cochlear nucleus

Ryugo¹,

Parks²

2003

Brain Research Bulletin

115

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The auditory nerve of birds and mammals exhibits differences and similarities, but given the millions of years since the two classes diverged from a common ancestor, the similarities are much more impressive than the differences. The avian nerve is simpler than that of mammals, but share many fundamental features including principles of development, structure, and physiological properties. Moreover, the available evidence shows that the human auditory nerve follows this same general organizational plan. Equally impressive are reports that homologous genes in worms, flies, and mice exert the same heredity influences in man. The clear implication is that animal studies will produce knowledge that has a direct bearing on the human condition.

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“…The avian auditory system has two anatomically and physiologically distinct cochlear nuclei, nucleus magnocellularis (NM) and nucleus angularis (NA). NM neurons lack dendrites and contain end bulbs of Held, whereas NA neurons have dendrites and bouton-type synapses (Parks, 1981;Jhaveri and Morest, 1982;Takahashi and Konishi, 1988a;Carr and Boudreau, 1993). NM neurons show phase locking, whereas NA neurons do not except for very low frequencies (Sachs and Sinnott, 1978;Sullivan and Konishi, 1984a;Konishi et al, 1985;Warchol and Dallos, 1990).…”

Section: Abstract: Owl; Sound Localization; Nucleus Laminaris; Intermentioning

confidence: 99%

Effects of Interaural Intensity Difference on the Processing of Interaural Time Difference in the Owl’s Nucleus Laminaris

1997

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Interaural time and intensity differences (ITD and IID) are processed independently in the owl's auditory system. This paper examines whether this independence is established in nucleus laminaris (NL), the first site of ITD processing. A plot of discharge rate against time difference (ITD curve) is sinusoidal in NL. The ITDs that produce the peaks are called the most favorable ITDs, and those that produce the troughs are called the least favorable ITDs. IID had little effect on the discharge rates of laminaris neurons for the most and least favorable ITDs. The degree of peak-trough modulation changed slightly with variation in IID. In contrast, IID in tonal stimuli affected the temporal aspect of ITD curves depending on the difference between the stimulus frequency and the neuron's best frequency (BF). For frequencies below BF, IID caused large and systematic shifts in ITD toward the ear in which the sound was louder, whereas for frequencies above BF, IID caused small shifts in ITD toward the opposite ear. IID had little effect on ITD curves taken with BF or broadband noise. These results can be largely accounted for by the effects of frequency and intensity on the timing of impulses at the level of the cochlear nuclei. Thus, the processing of ITD by NL neurons is independent of IID for behaviorally relevant stimuli, because the timing of impulses is insensitive to sound level when the signal is broadband. Key words: owl; sound localization; nucleus laminaris; interaural time difference; interaural intensity difference; parallel pathwaysParallel processing of information is an important operation in many sensory systems (see, for example, owl's auditory system: Takahashi et al., 1984; monkey visual system: Maunsell et al., 1990;Merigan and Maunsell, 1993; fish electrosensory system: Heiligenberg, 1991). The barn owl's auditory brainstem offers a relatively simple system in which to analyze the relationship between parallel pathways. The owl uses interaural time and intensity differences (ITD and IID) for sound localization (Moiseff, 1989b). The independence of these cues is important for the species, because they code for different spatial coordinate axes, ITD mainly for azimuth and IID mainly for elevation. ITD and IID are processed in separate parallel pathways that start at the level of the cochlear nucleus. The avian auditory system has two anatomically and physiologically distinct cochlear nuclei, nucleus magnocellularis (NM) and nucleus angularis (NA). NM neurons lack dendrites and contain end bulbs of Held, whereas NA neurons have dendrites and bouton-type synapses (Parks, 1981;Jhaveri and Morest, 1982;Takahashi and Konishi, 1988a;Carr and Boudreau, 1993). NM neurons show phase locking, whereas NA neurons do not except for very low frequencies (Sachs and Sinnott, 1978;Sullivan and Konishi, 1984a;Konishi et al., 1985;Warchol and Dallos, 1990). The time-and intensity-processing pathways converge in the inferior colliculus, where neurons selective for combinations of ITD and IID are found. Partial inactivat...

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Neuronal architecture in nucleus magnocellularis of the chicken auditory system with observations on nucleus laminaris: A light and electron microscope study

Cited by 151 publications

References 34 publications

Heterogeneous Calretinin Expression in the Avian Cochlear Nucleus Angularis

Heterogeneous Calretinin Expression in the Avian Cochlear Nucleus Angularis

Primary innervation of the avian and mammalian cochlear nucleus

Effects of Interaural Intensity Difference on the Processing of Interaural Time Difference in the Owl’s Nucleus Laminaris

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