Differentiation of the bulbar motor nuclei and the coincident development of associated root fibers in the rabbit

Kimmel, Donald L.

doi:10.1002/cne.900720104

Cited by 54 publications

(16 citation statements)

References 36 publications

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“…Paramedian basal TH-IR cells in r5 and r6 express the marker more strongly and seem to be invaded by the migrating TH-negative mass of facial motoneurons (asterisks in Fig. 5C; in mammals, the facial motor primordium contains cells born in r4 and r5, which subsequently translocate caudally into r6; Kimmel, 1940;Gilland and Baker, 1993). The most lateral of these basal TH-IR cells of r6 also translocate ventrolaterally toward the brain surface, approaching the subsequent locus of the caudal A5 cell group (compare Fig.…”

Section: Stages 16-17mentioning

confidence: 99%

Early neuromeric distribution of tyrosine-hydroxylase-immunoreactive neurons in human embryos

1998

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A segmental mapping of brain tyrosine-hydroxylase-immunoreactive (TH-IR) neurons in human embryos between 4.5 and 6 weeks of gestation locates with novel precision the dorsoventral and anteroposterior topography of the catecholamine-synthetizing primordia relative to neuromeric units. The data support the following conclusions. (1) All transverse sectors of the brain (prosomeres in the forebrain, midbrain, rhombomeres in the hindbrain, spinal cord) produce TH-IR neuronal populations. (2) Each segment shows peculiarities in its contribution to the catecholamine system, but there are some overall regularities, which reflect that some TH-IR populations develop similarly in different segments. (3) Dorsoventral topology of the TH-IR neurons indicates that at least four separate longitudinal zones (in the floor and basal plates and twice in the alar plate) found across most segments are capable of producing the TH-IR phenotype. (4) Basal plate TH-IR neurons tend to migrate intrasegmentally to a ventrolateral superficial position, although some remain periventricular; those in the brainstem are related to motoneurons of the oculomotor and branchiomotor nuclei. (5) Some alar TH-IR populations migrate superficially within the segmental boundaries. (6) Most catecholaminergic anatomical entities are formed as fusions of smaller segmental components, each of which show similar histogenetic patterns. A nomenclature is proposed that partly adheres to previous terminology but introduces the distinction of embryologically different cell populations and unifies longitudinally analogous entities. Such a model, as presented in the present study, is convenient for resolving problems of homology of the catecholamine system across the diversity of vertebrate forms.

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Section: Stages 16-17mentioning

confidence: 99%

Early neuromeric distribution of tyrosine-hydroxylase-immunoreactive neurons in human embryos

1998

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“…However, there is only scattered information regarding the sites of termination of afferent fibres from nerves involved in respiratory and cardiovascular control. There have been anatomical studies of the distribution of central endings of the vagus and glossopharyngeal nerves (Kimmel, 1940(Kimmel, , 1941Torvik, 1956Torvik, , 1957Cottle, 1964), as well as electrophysiological studies on potentials evoked in the brain stem by stimulation of the vagus and superior laryngeal nerves (Anderson & Berry, 1956;Rudomin, 1967;Porter, 1963) and the aortic nerve (Anderson & Berry, 1956;Rudomin, 1967;Crill & Reis, 1968). Humphrey (1966Humphrey ( , 1967 has studied the field and unit potentials evoked from the sinus nerve with special reference to baroreceptor afferent fibres, and Miura & Reis (1968, 1969 and Crill & Reis (1968) have also reported some results on the central distribution of afferent fibres of the sinus nerve.…”

Section: Introductionmentioning

confidence: 99%

Field potentials evoked in the brain stem of the cat by stimulation of the carotid sinus, glossopharyngeal, aortic and superior laryngeal nerves

Biscoe¹,

Sampson²

1970

The Journal of Physiology

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SUlMMARY1. In a primarily topographical study, the field potentials evoked in the brain stem of the cat by stimulation of the sinus, glossopharyngeal (IX), aortic and superior laryngeal (SLN) nerves have been recorded with glass micro-electrodes.2. Extracellular negative potentials were evoked in the region of the nucleus of the tractus solitarius and in the lateral reticular formation (LRF) by electrical stimulation of all four nerves. There were differences in the form of these potentials amongst the nerves, particularly between sinus-IX and aortic-SLN. The potentials were identified as post-synaptic with early and late components and were sometimes preceded by an afferent volley.3. Extracellular positive potentials were evoked in the subnucleus reticularis medialis medullae oblongatae and the nucleus reticularis gigantocellularis. Intracellularly recorded hyperpolarizations recorded from six cells had the same time course as the extracellular positivity.Spontaneously active cells encountered in these regions were sometimes depressed for the duration of the positivity.4. Each of the above field potentials was maximal in the region of Horsley-Clarke A. P. co-ordinates -10 to -13 mm.5. At A.P. co-ordinates of -15 to -17 mm negativity showing posttetanic potentiation was evoked, at latencies similar to the negativity in the LRF, in the commissural nucleus of Cajal, the dorsolateral reticular formation and the medial reticulo-spinal tract.6. Negative potentials were evoked in the contralateral LRF.

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“…Conse quently. in a number of papers, hindbrain segments '1-5' or 'a -c ' correspond to von Kupffer's rhombomeres 2-6 [31][32][33]. Hindbrain segments caudal to the posterior border of r6 are not so readily identifiable.…”

Section: General Pattern Of Hindbrain Segmentation In Vertebratesmentioning

confidence: 99%

Conservation of Neuroepithelial and Mesodermal Segments in the Embryonic Vertebrate Head

Gilland¹,

Baker²

1993

Cells Tissues Organs

166

148

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The organization of embryonic efferent cranial nerves is addressed here by inter-species comparison of segmentally patterned neuromeres, efferent neuronal populations and early mesodermal sources of target muscles. The segmental constancy of these three structural patterns is evaluated for elasmobranch teleost, reptile, bird and mammal embryos and compared with the segmentally restricted expression patterns of Hox genes. A conserved series of hindbrain neuroepithelial segments (rhombomeres) is present in all of these taxa. Dye-labeling experiments demonstrate that the segmental locations of efferent neurons projecting through individual cranial nerves are likewise highly conserved. Notable segmental variation is however shown in the location of the VI and IX–XII motoneurons, suggesting the likelihood of homeotic-like changes in relations between rhombomere and neuronal ‘identity’ during vertebrate evolution. Since experimentally induced shifts in expression borders of Hox genes appear to be correlated with alterations in segment identity and/or neuronal phenotype, the need for further examination of segmental locations of specific neuronal groups and the segmental expression patterns of Hox genes between species is emphasized. Comparison of early cranial mesodermal subdivisions in elasmobranchs with descriptions of somitomeres in amniotes suggests that a series of axially unique mesodermal populations may also be conserved throughout vertebrates. The possibility is raised that common mechanisms of axial specification may underlie the initial appearance of segmental patterning in both neural and mesodermal layers during gastrulation. Implications of these conserved patterns for understanding the phylogenetic origin of the vertebrate head are briefly discussed.

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Differentiation of the bulbar motor nuclei and the coincident development of associated root fibers in the rabbit

Cited by 54 publications

References 36 publications

Early neuromeric distribution of tyrosine-hydroxylase-immunoreactive neurons in human embryos

Early neuromeric distribution of tyrosine-hydroxylase-immunoreactive neurons in human embryos

Field potentials evoked in the brain stem of the cat by stimulation of the carotid sinus, glossopharyngeal, aortic and superior laryngeal nerves

Conservation of Neuroepithelial and Mesodermal Segments in the Embryonic Vertebrate Head

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