The Motoneuronal Organization of the Spinal Accessory Nuclear Complex

Krammer, Eva B.; Lischka, Martin F.; Egger, Thomas; Riedl, Maria; Gruber, Helmut

doi:10.1007/978-3-662-10362-3

Cited by 17 publications

(38 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This observation is consistent with previous reports by Satomi et al (1985) and Vanner and Rose (1984), who found labelled cells in C6, but is not consistent with reports by other investigators (e.g., Holomanova et al, 1972;Rapoport, 1978), who described a shorter motor column ending in C5. The caudal limit of C6 rather than C5 is consistent with descriptions of the rodent SAN, in which labelled cells were reported as far caudally as C6 (Kitamura and Sakai, 1982;Matesz and Szekely, 1983) or even C7 (Krammer et al, 1987;Charlton et al, 1988) following tracer injections into muscles supplied by the spinal accessory nerve.…”

Section: Rh and Lssupporting

confidence: 83%

“…However, some have reported that the nucleus is formed by a single column in which motoneurons supplying different heads intermingle (Ruminska-Kowalska et al, 1976;Augustine and White, 1986;Brichta et al, 1987). Others describe it as a pair of mediolaterally separated columns in which the motoneurons supplying different muscle heads are segregated from one another (Rapoport, 1978;Krammer et al, 1987) or are intermixed (Kitamura and Sakai, 1982). A better knowledge of the intraspinal distribution of motoneurons supplying a full range of neck muscles is an important prerequisite for neuroanatomical and electrophysiological studies to understand the orchestration of muscles that subserve head movement by acting at different levels of the cervical vertebral column.…”

mentioning

confidence: 95%

See 1 more Smart Citation

Distribution of motoneurons supplying feline neck muscles taking origin from the shoulder girdle

1997

View full text Add to dashboard Cite

A combination of fluorescent retrograde tracers and horseradish peroxidase (HRP) was used to compare the spinal distributions of motoneurons supplying shoulder muscles with attachments to the skull and cervical spinal cord that suggest a significant role in head movement. Two muscles, the rhomboideus and the levator scapulae, were innervated by multiple segmental nerve bundles that entered the muscles at different rostrocaudal locations. Motoneurons that were labelled retrogradely from rhomboideus nerve bundles formed a single, long column in the ventral horn from C4 to C6, lateral to previously studied motor nuclei supplying deep neck muscles. When different tracers were used to differentiate motoneurons supplying specific nerve bundles, discrete subnuclei could be identified that were organized in a rostrocaudal sequence corresponding to the rostrocaudal order of the nerve bundles. Levator scapulae motoneurons formed a second elongate column immediately lateral to the rhomboidues motor nucleus. Three other muscles, that trapezius, sternomastoideus, and cleidomastoideus, were supplied by cranial nerve XI. Labelled motoneurons from these muscles formed a single column from the spinomedullary junction to middle C6. Within this column, the three motor nuclei supplying the sternomastoideus, cleidomastoideus, and trapezius were laminated mediolaterally. Sternomastoideus and cleidomastoideus motoneurons were confined to upper cervical segments, whereas trapezius motoneurons were found from C1 to C6. In C1 and C6, the motoneuron column was located centrally in the gray matter, but, between C2 and C5, the column lay on the lateral wall of the ventral horn in a position dorsolateral to motor nuclei supplying the rhomboideus and the deeper neck muscles. The findings in this study suggest that descending and propriospinal systems responsible for coordinating head movement may have to descend as far caudally as C6 if they are to project onto muscles controlling the mobility of the lower neck.

show abstract

Section: Rh and Lssupporting

confidence: 83%

mentioning

confidence: 95%

Distribution of motoneurons supplying feline neck muscles taking origin from the shoulder girdle

1997

View full text Add to dashboard Cite

show abstract

“…The branchial motoneurons of the spinal accessory nucleus (SAN) are generated in the ventral neural tube at the C4-C3 level (Krammer et al, 1987;Liinamaa et al, 1997) together with somatic motoneurons of the median motor column (MMC) (Callister et al, 1987) and phrenic motoneurons (Goshgarian and Rafols, 1981). At midgestation, cell bodies of MMC neurons are located in a ventromedial position and project axons ventrally through segmental motor nerves, while SAN neurons migrate to a dorsolateral position and project axons via the spinal accessory nerve.…”

Section: Nkx29 Mutants Show Defects Of the Spinal Accessory Nervementioning

confidence: 99%

Targeted disruption of the homeobox geneNkx2.9reveals a role in development of the spinal accessory nerve

et al. 2003

View full text Add to dashboard Cite

The homeodomain-containing transcription factor Nkx2.9 is expressed in the ventralmost neural progenitor domain of the neural tube together with the related protein Nkx2.2 during early mouse embryogenesis. Cells within this region give rise to V3 interneurons and visceral motoneurons in spinal cord and hindbrain, respectively. To investigate the role of the Nkx2.9 gene, we generated a mutant mouse by targeted gene disruption. Homozygous mutant animals lacking Nkx2.9 were viable and fertile with no apparent morphological or behavioral phenotype. The distribution of neuronal progenitor cells and differentiated neurons in spinal cord was unaffected in Nkx2.9-deficient animals. This finding is in contrast to Nkx2.2-null mutants, which have been shown to exhibit ventral to dorsal transformation of neuronal cell fates in spinal cord. Our results suggest that specification of V3 interneurons in the posterior CNS does not require Nkx2.9, most probably because of functional redundancy with the co-expressed Nkx2.2 protein. In hindbrain, however, absence of Nkx2.9 resulted in a significantly altered morphology of the spinal accessory nerve (XIth), which appeared considerably shorter and thinner than in wild-type animals. Consistent with this phenotype, immature branchial motoneurons of the spinal accessory nerve, which normally migrate from a ventromedial to a dorsolateral position within the neural tube, were markedly reduced in Nkx2.9-deficient embryos at E10.5, while ventromedial motor column cells were increased in numbers. In addition, the vagal and glossopharyngeal nerves appeared abnormal in approximately 50% of mutant embryos, which may be related to the observed reduction of Phox2b expression in the nucleus ambiguus of adult mutant mice. From these observations, we conclude that Nkx2.9 has a specific function in the hindbrain as determinant of the branchial motoneuron precursor cells for the spinal accessory nerve and possibly other nerves of the branchial-motor column. Like other Nkx genes expressed in the CNS, Nkx2.9 seems to be involved in converting positional information into cell fate decisions.

show abstract

“…The origin of the cucullaris muscle has been the subject of considerable debate (Krammer et al, 1987). Origins as diverse as the branchial arches, somites and the lateral plate mesoderm have all been proposed, evidenced often by innervation (Addens, 1933;Allis, 1897;Couly et al, 1993;Derjugin, 1908;Edgeworth, 1911;Edgeworth, 1926;Favaro, 1903;Fuerbringer, 1897;Gegenbaur, 1898;Harrison, 1918;Huang et al, 1997;Huang et al, 2000;Lewis, 1910;Luther and Lubosch, 1938;Noden, 1983;Noden and Francis-West, 2006;Piekarski and Olsson, 2007).…”

Section: Introductionmentioning

confidence: 99%

The occipital lateral plate mesoderm is a novel source for vertebrate neck musculature

et al. 2010

View full text Add to dashboard Cite

SUMMARYIn vertebrates, body musculature originates from somites, whereas head muscles originate from the cranial mesoderm. Neck muscles are located in the transition between these regions. We show that the chick occipital lateral plate mesoderm has myogenic capacity and gives rise to large muscles located in the neck and thorax. We present molecular and genetic evidence to show that these muscles not only have a unique origin, but additionally display a distinct temporal development, forming later than any other muscle group described to date. We further report that these muscles, found in the body of the animal, develop like head musculature rather than deploying the programme used by the trunk muscles. Using mouse genetics we reveal that these muscles are formed in trunk muscle mutants but are absent in head muscle mutants. In concordance with this conclusion, their connective tissue is neural crest in origin. Finally, we provide evidence that the mechanism by which these neck muscles develop is conserved in vertebrates.

show abstract

The Motoneuronal Organization of the Spinal Accessory Nuclear Complex

Cited by 17 publications

References 0 publications

Distribution of motoneurons supplying feline neck muscles taking origin from the shoulder girdle

Distribution of motoneurons supplying feline neck muscles taking origin from the shoulder girdle

Targeted disruption of the homeobox geneNkx2.9reveals a role in development of the spinal accessory nerve

The occipital lateral plate mesoderm is a novel source for vertebrate neck musculature

Contact Info

Product

Resources

About