Early development and migration of the trigeminal motor nucleus in the chick embryo

1980 ◽  
Vol 189 (1) ◽  
pp. 61-99 ◽  
Author(s):  
Marieta B. Heaton ◽  
Sally A. Moody
Keyword(s):  
Chick Embryo ◽  
Early Development ◽  
Motor Nucleus ◽  
Trigeminal Motor Nucleus ◽  
And Migration

Early Development and Tissue-Specific Patterns of Insulin Binding in Chick Embryo*

Endocrinology ◽  
1984 ◽  
Vol 115 (4) ◽  
pp. 1315-1323 ◽  
Author(s):  
S. ANNE HENDRICKS ◽  
FLORA DE PABLO ◽  
JESSE ROTH
Keyword(s):  
Chick Embryo ◽  
Early Development ◽  
Insulin Binding ◽  
Tissue Specific

A radioautographic study of the development of the somite in the chick embryo

Development ◽  
1968 ◽  
Vol 19 (2) ◽  
pp. 217-226
Author(s):  
Jan Langman ◽  
George R. Nelson
Keyword(s):  
Chick Embryo ◽  
Controversial Issue ◽  
Lateral Direction ◽  
Total Length ◽  
Difference Of Opinion ◽  
And Migration

Considerable difference of opinion exists about the origin of the various components of the somite. According to Williams (1910), Hamilton (1952) and Boyd (1960), the cells of the myotome originate in the dorso-medial angle of the somite wall and migrate beneath the dermatome in ventro-lateral direction. A group of older investigators (Remak, 1855; His, 1888; Bardeen, 1900) state, however, that the myotome cells originate not only in the dorso-medial angle but also along the total length of the dorsal somite wall, formed by the dermatome. Similarly, in birds whether the myotome extends in ventro-lateral direction by growth and migration of existing cells (Engert, 1900; Williams, 1910) or by differentiation of locally found mesoderm cells into myoblasts (Straus & Rawles, 1953) remains even at present a controversial issue.

A radioautographic analysis of the migration and fate of cells derived from the occipital somites in the chick embryo with specific reference to the development of the hypoglossal musculature

Development ◽  
1970 ◽  
Vol 24 (3) ◽  
pp. 455-466
Author(s):  
R. D. Hazelton
Keyword(s):  
Chick Embryo ◽  
Dorsal Surface ◽  
Lateral Position ◽  
Migration Pattern ◽  
Specific Reference ◽  
Specific Marker ◽  
Differential Growth ◽  
Pericardial Cavity ◽  
And Migration ◽  
Pharyngeal Area

The migration pattern and fate of cells of the occipital somites and overlying ectoderm have been described for the chick embryo with particular reference to the development of the hypoglossal musculature. Tritium-labelled thymidine (0·5–10 µCi per egg) was used as a cell-specific marker. Occipital somites (2–5) with overlying ectoderm were transplanted orthotopically from labelled donor embryos to unlabelled host embryos (Hamburger & Hamilton, stage 9–10). The embryos were incubated, for varying lengths of time (24 h-5 days), sacrificed, sectioned and the migration pattern and fate of the labelled cells determined radioautographically. It appears that the hypoglossal as well as other hypopharyngeal musculature originates from the occipital somites. The mesodermal migration pattern extended from the occipital somite region in a ventroposterior direction to the dorsal surface of the pericardial cavity posterior to the expanded portion of the pharynx. At this position a so-called hypoglossal cord formed on each side which ran anteriorly to the level of the second pharyngeal pouch where it turned medially and together with the cord from the other side entered the pharyngeal area of the embryo. This material apparently forms the intrinsic musculature of the tongue. The mesodermal movements are attributed to differential growth movements of the areas concerned as well as to active cell mutiplication and migration. Selective embryonic neuronal staining was undertaken to study the relationship between the migrating hypoglossal cord and nerve. The cord preceded the nerve in its migration. There is an occipital somitic contribution to the primitive meninx, to the endothelial walls of developing blood vessels, possibly to microglial cells and to the cartilage surrounding the notocord. The occipital ectoderm expands dorso-anteriorly and ventro-laterally. In the ventro-lateral position as contact is made with the pharyngeal endoderm a placode is formed which contributes cells to the nodose ganglion of the tenth cranial nerve. There is no other contribution of the ectoderm to the underlying tissues.

The organization and activity patterns of the anterior and posterior heads of the guinea pig digastric muscle

1987 ◽  
Vol 58 (3) ◽  
pp. 496-509 ◽  
Author(s):  
A. Lev-Tov ◽  
M. Tal
Keyword(s):  
Guinea Pig ◽  
Activity Patterns ◽  
Motor Nucleus ◽  
Digastric Muscle ◽  
Fiber Types ◽  
Jaw Movements ◽  
Cross Sectional ◽  
Trigeminal Motor Nucleus ◽  
Facial Motor Nucleus ◽  
Early Activity

The structure and activity patterns of the anterior and posterior heads of the guinea pig digastric muscle (DG) were studied in ketamine-anesthetized guinea pigs. Collagen staining of longitudinal and transverse sections of the muscle revealed that the guinea pig DG is comprised of a unicompartmental anterior head (ADG) and a multicompartmental posterior head (PDG). The two heads are separated by a thin tendinous inscription that, unlike the intermediate tendon of the DG in humans, is not attached to the hyoid bone. The motor nuclei of the guinea pig DG were reconstructed using retrograde labeling with horseradish peroxidase. The motoneurons of the ADG were clustered in a longitudinal column within the trigeminal motor nucleus. The motoneurons of the PDG were segregated into two clusters within the facial motor nucleus. The cross-sectional areas of the ADG and PDG motoneuron somata exhibited unimodal frequency distributions and the average soma area was larger for ADG than PDG motoneurons. Histochemical characterization of ADG and PDG revealed that the two muscle heads contained the three main histochemical types of muscle fibers identified in limb muscles. The frequency distribution of fiber types in ADG and PDG were not significantly different. Both muscle heads were predominantly fast with slow oxidative fibers accounting for only 1.1 and 0.3% of the fibers in narrow dorsal regions of ADG and PDG, respectively, and 13.6 and 12.9% in the more ventral regions of ADG and PDG, respectively. Simultaneous recordings of EMGs from the ADG and PDG were carried out during spontaneously occurring rhythmical jaw movements. These recordings revealed a high degree of synchrony between the activities of the two heads, although differences were observed in the onset and duration of the EMG bursts. Activity in the PDG preceded activity in the ADG in most of the rhythmical cycles and persisted longer. The differences in latencies of time-locked EMGs evoked in the ADG and PDG by four-pulse cortical stimulation were much smaller than those observed between the activity bursts of the two heads during rhythmical jaw movements. It is suggested that the early activity in the PDG is accounted for by shorter central conduction times in the pathways onto it and/or by higher recruitability of its motor units. The early activity in PDG may serve to optimize the location of ADG on its length-tension curve prior to and during the active state.

scholarly journals Properties and Interconnections of Trigeminal Interneurons of the Lateral Pontine Reticular Formation in the Rat

2001 ◽  
Vol 86 (5) ◽  
pp. 2583-2596 ◽  
Author(s):  
M.-J. Bourque ◽  
A. Kolta
Keyword(s):  
Electrical Stimulation ◽  
Reticular Formation ◽  
Motor Pattern ◽  
High Frequency Stimulation ◽  
Motor Nucleus ◽  
Trigeminal Motor Nucleus ◽  
Postsynaptic Potentials ◽  
Frequency Stimulation ◽  
Stimulation Of

Numerous evidence suggests that interneurons located in the lateral tegmentum at the level of the trigeminal motor nucleus contribute importantly to the circuitry involved in mastication. However, the question of whether these neurons participate actively to genesis of the rhythmic motor pattern or simply relay it to trigeminal motoneurons remains open. To answer this question, intracellular recordings were performed in an in vitro slice preparation comprising interneurons of the peritrigeminal area (PeriV) surrounding the trigeminal motor nucleus (NVmt) and the parvocellular reticular formation ventral and caudal to it (PCRt). Intracellular and extracellular injections of anterograde tracers were also used to examine the local connections established by these neurons. In 97% of recordings, electrical stimulation of adjacent areas evoked a postsynaptic potential (PSP). These PSPs were primarily excitatory, but inhibitory and biphasic responses were also induced. Most occurred at latencies longer than those required for monosynaptic transmission and were considered to involve oligosynaptic pathways. Both the anatomical and physiological findings show that all divisions of PeriV and PCRt are extensively interconnected. Most responses followed high-frequency stimulation (50 Hz) and showed little variability in latency indicating that the network reliably distributes inputs across all areas. In all neurons but one, excitatory postsynaptic potentials (EPSPs) or inhibitory postsynaptic potentials (IPSPs) were also elicited by stimulation of NVmt, suggesting the existence of excitatory and inhibitory interneurons within the motor nucleus. In a number of cases, these PSPs were reproduced by local injection of glutamate in lieu of the electrical stimulation. All EPSPs induced by stimulation of PeriV, PCRt, or NVmt were sensitive to ionotropic glutamate receptor antagonists 6-cyano-7-dinitroquinoxaline and d,l-2-amino-5-phosphonovaleric acid, while IPSPs were blocked by bicuculline and strychnine, antagonists of GABAA and glycine receptors. Examination of PeriV and PCRt intrinsic properties indicate that they form a fairly uniform network. Three types of neurons were identified on the basis of their firing adaptation properties. These types were not associated with particular regions. Only 5% of all neurons showed bursting behavior. Our results do not support the hypothesis that neurons of PeriV and PCRt participate actively to rhythm generation, but suggest instead that they are driven by rhythmical synaptic inputs. The organization of the network allows for rapid distribution of this rhythmic input across premotoneuron groups.

Segmental origin and migration of neural crest cells in the hindbrain region of the chick embryo

Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1281-1291 ◽  
Author(s):  
A. Lumsden ◽  
N. Sprawson ◽  
A. Graham
Keyword(s):  
Chick Embryo ◽  
Neural Crest ◽  
Fate Map ◽  
Membrane Probe ◽  
Vital Dye ◽  
Video Fluorescence Microscopy ◽  
Dye Analysis ◽  
And Migration ◽  
Neural Crest Migration ◽  
Branchial Region

A vital dye analysis of cranial neural crest migration in the chick embryo has provided a positional fate map of greater resolution than has been possible using labelled graft techniques. Focal injections of the fluorescent membrane probe DiI were made into the cranial neural folds at stages between 3 and 16 somites. Groups of neuroepithelial cells, including the premigratory neural crest, were labelled by the vital dye. Analysis of whole-mount embryos after 1–2 days further development, using conventional and intensified video fluorescence microscopy, revealed the pathways of crest cells migrating from mesencephalic and rhombencephalic levels of the neuraxis into the subjacent branchial region. The patterns of crest emergence and emigration correlate with the segmented disposition of the rhombencephalon. Branchial arches 1, 2 and 3 are filled by crest cells migrating from rhombomeres 2, 4 and 6 respectively, in register with the cranial nerve entry/exit points in these segments. The three streams of ventrally migrating cells are separated by alternating regions, rhombomeres 3 and 5, which release no crest cells. Rostrally, rhombomere 1 and the caudal mesencephalon also contribute crest to the first arch, primarily to its upper (maxillary) component. Both r3 and r5 are associated with enhanced levels of cell death amongst cells of the dorsal midline, suggesting that crest may form at these levels but is then eliminated. Organisation of the branchial region is thus related by the dynamic process of neural crest immigration to the intrinsic mechanisms that segment the neuraxis.

Early development of the hypoglossal nerve in the chick embryo as observed by the whole-mount nerve staining method

1988 ◽  
Vol 182 (2) ◽  
pp. 155-168 ◽  
Author(s):  
Shigeru Kuratani ◽  
Shigenori Tanaka ◽  
Yuji Ishikawa ◽  
Chosei Zukeran
Keyword(s):  
Chick Embryo ◽  
Early Development ◽  
Hypoglossal Nerve ◽  
Staining Method ◽  
Whole Mount ◽  
Nerve Staining
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