Inhibition of cell spreading on the band of extracellular fibres in early chick and quail embryos

1985 ◽  
Vol 74 (1) ◽  
pp. 37-50
Author(s):  
L. Andries ◽  
C. Vanroelen ◽  
J. Van Hoof ◽  
L. Vakaet
Keyword(s):  
Deep Layer ◽  
Single Cells ◽  
Middle Layer ◽  
Ventral Surface ◽  
Fibrous Band ◽  
Cell Behaviour ◽  
Lateral Border ◽  
Extracellular Fibrils ◽  
Chick And Quail Embryos ◽  
Area Pellucida

The ventral surface of the upper layer shows a band of extracellular fibrils around the anterior and lateral border of the area pellucida during gastrulation of the chick embryo. Using scanning electron microscopy, we found that this disposition is correlated with the motility of the middle-layer cells of gastrulating chick and quail embryos. Outside the fibrous band, single middle-layer cells and a sheet of mesoblast cells were spread out and possessed lamellae. Single cells on the fibrous band did not form lamellae. The same cell behaviour was obtained with the explants of deep layer on the fibrous band. The fibrous band is assumed to operate as a barrier that inhibits cell motility during gastrulation.

scholarly journals Vasculogenesis in the early quail blastodisc as studied with a monoclonal antibody recognizing endothelial cells

Development ◽  
1987 ◽  
Vol 100 (2) ◽  
pp. 339-349 ◽  
Author(s):  
L. Pardanaud ◽  
C. Altmann ◽  
P. Kitos ◽  
F. Dieterlen-Lievre ◽  
C.A. Buck
Keyword(s):  
Monoclonal Antibody ◽  
Endothelial Cells ◽  
Single Cells ◽  
Primitive Streak ◽  
Vascular Network ◽  
Vascular Tree ◽  
Somite Stage ◽  
Area Vasculosa ◽  
Haemopoietic Cells ◽  
Area Pellucida

QH1, a monoclonal antibody that recognizes quail endothelial and haemopoietic cells, was applied to quail blastodiscs in toto, in order to analyse by immunofluorescence the emergence of the vascular tree. The first endothelial cells were detected in the area opaca at the headfold stage and in the area pellucida at the 1-somite stage. Single cells then interconnected progressively, especially in the anterior intestinal portal and along the somites building up the linings of the heart and dorsal aortas. This study demonstrates that endothelial cells differentiate as single entities 4 h earlier in development than hitherto detected and that the vascular network forms secondarily. The horseshoe shape of the extraembryonic area vasculosa is also a secondary acquisition. A nonvascularized area persists until later (at least the 14-somite stage) in the region of the regressing primitive streak.

scholarly journals Gross anatomy of the narial and labial musculatures of one humped Camel (Camelus dromedarius)

2016 ◽  
Vol 33 (04) ◽  
pp. 171-178
Author(s):  
Z. Adam ◽  
A. Awaad ◽  
M. Tawfiek ◽  
A. Ibrahim
Keyword(s):  
Deep Layer ◽  
Gross Anatomy ◽  
Middle Layer ◽  
Superficial Layer ◽  
Living Conditions ◽  
Camelus Dromedarius ◽  
Nerve Supply ◽  
Levator Labii Superioris ◽  
The One

Abstract Introduction: The objective of this study was to clarify the anatomy of the narial and labial musculatures of the one-humped camel (Camelus dromedarius) and their nerve supply. Materials and Methods: Sixteen head specimens from adult and symptomatically healthy camels of both sexes were used. The muscles of the nostrils and lips were carefully dissected and illustrated to demonstrate their origin, insertion and relations. The nerves in this area were also dissected to show their branches and distribution. Results: The dissection of these regions revealed that their muscles were arranged in three layers; the superficial layer included M. dilator naris apicalis, M. dilator naris medialis and M. levator nasolabialis, the middle layer was formed of maxillo-labial group of muscles (M. levator labii superioris, M. dilator naris lateralis and M. depressor labii superioris) and the deep layer was formed by M. lateralis nasi. Moreover, the lips had M. orbicularis oris, M. incisivus superioris, M. incisivus inferioris and M. mentalis, however, the M. depressor labii inferioris was absent in the animal under investigation. The muscles of nostrils and lips were innervated by N. trigeminus (V) and N. facialis (VII). Conclusion: The arrangement of the narial and labial muscles is unique and may relate to its living conditions of frequent sand-storms and direct sun rays, where the camel is the only domesticated animal known for its ability to close its nostril.

Microstimulation of a Neural-Network Model for Visually Guided Saccades

1989 ◽  
Vol 1 (4) ◽  
pp. 317-326 ◽  
Author(s):  
Sabrina J. Goodman ◽  
Richard A. Andersen
Keyword(s):  
Neural Network ◽  
Eye Movements ◽  
Network Model ◽  
Neural Network Model ◽  
Posterior Parietal Cortex ◽  
Single Cells ◽  
Middle Layer ◽  
Retinal Position ◽  
Area 7A ◽  
The Brain

Microstimulation of many saccadic centers in the brain produces eye movements that are not consistent with either a strictly retinal or strictly head-centered coordinate coding of eye movements. Rather, stimulation produces some features of both types of coordinate coding. Recently we demonstrated a neural network model that was trained to localize the position of visual stimuli in head-centered coordinates at the output using inputs of eye and retinal position similar to those converging on area 7a of the posterior parietal cortex of monkeys (Zipser & Andersen 1988; Andersen & Zipser 1988). Here we show that microstimulation of this trained network, achieved by fully activating single units in the middle layer, produces “saccades” that are very much like the saccades produced by stimulating the brain. The activity of the middle-layer units can be considered to code the desired location of the eyes in head-centered coordinates; however, stimulation of these units does not produce the saccades predicted by a classical head-centered coordinate coding because the location in space appears to be coded in a distributed fashion among a population of units rather than explicitly at the level of single cells.

The Micro-Mechanical Behavior of Articular Cartilage under Continuous Sliding Load

2013 ◽  
Vol 395-396 ◽  
pp. 654-657
Author(s):  
Peng Peng Xiao ◽  
Li Lan Gao ◽  
Zhi Dong Liu ◽  
Chun Qiu Zhang
Keyword(s):  
Articular Cartilage ◽  
Connective Tissue ◽  
Deep Layer ◽  
Compressive Strain ◽  
Middle Layer ◽  
Superficial Layer ◽  
Image Correlation ◽  
Daily Activities ◽  
Normal Displacement ◽  
Dic Technique

As a viscoelastic and nonlinear connective tissue, articular cartilage bears continuous sliding load in the daily activities. The optimized digital image correlation (DIC) technique was applied to investigate the effect of sliding rate and compressive strain on the normal displacement of different layers in pig articular cartilage under sliding load. The normal displacements of different layers in cartilage increase gradually with sliding going on with given sliding rate and compressive strain. Experiments showed that the normal displacement of superficial layer is the largest, the normal displacement of deep layer is the smallest and the normal displacement of middle layer is between superficial layer and deep layer, and found that the normal displacements of different layers in cartilage increase with increasing compressive strains, but decrease with increasing sliding rates. The normal displacement of different layers are different under continuous sliding load.

An abnormality of cell behaviour in human dystrophic muscle cultures: a time-lapse study

1979 ◽  
Vol 38 (1) ◽  
pp. 201-210
Author(s):  
R. Yasin ◽  
G. Van Beers ◽  
P.N. Riddle ◽  
D. Brown ◽  
G. Widdowson ◽  
...  
Keyword(s):  
Growth And Development ◽  
Single Cells ◽  
Time Lapse ◽  
Development Pattern ◽  
Dystrophic Muscle ◽  
Cell Behaviour ◽  
Cluster Development ◽  
Myotube Formation ◽  
Muscle Cultures ◽  
Insight Into

The initiation of monolayer mass cell cultures from adult human biopsies has revealed a striking abnormality in the growth and development pattern of muscle cultures from Duchenne-type dystrophy. This abnormality in cell behaviour was seen as early as 4 days in culture, well before myotube formation or confluence, and consisted of areas where cells clustered together in a multilayered mass rather than showing the typical monolayer distribution normally observed. To gain some insight into the mechanism of cell cluster development, we have examined such a culture by time-lapse cinematography and also the cell behaviour of other control cultures. The results of this study show that the clusters enlarged primarily by cell division and, to a lesser extent, by the acquisition of neighbouring cells. Furthermore, none of the single cells surrounding the clusters exhibited contact inhibition of movement. This behaviour was not observed in the other cultures examined. These findings could be indicative of an abnormality in the cell surface or cell-locomotory machinery of dystrophic cells.

Gross anatomical features of the sternum of green-winged macaw (Ara Chloroptera)

2015 ◽  
Vol 49 (6) ◽  
Author(s):  
A. R. Sreeranjini ◽  
N. Ashok ◽  
V. R. Indu ◽  
K. M. Lucy ◽  
S. Maya ◽  
...  
Keyword(s):  
Anterior Extremity ◽  
Dorsal Surface ◽  
Ventral Surface ◽  
Morphological Features ◽  
Posterior Border ◽  
Posterior Half ◽  
Lateral Border ◽  
Convex Surfaces ◽  
Anatomical Features ◽  
Anterior Half

The present study was conducted on the sternum of an eight year old, male Green-winged Macaw. The sternum was quadrilateral with dorsal concave and ventral convex surfaces and four borders. The dorsal surface presented numerous pneumatic foramina. The ventral surface furnished a large, boat shaped keel. The anterior extremity showed two facets for coracoid. The anterior and posterior borders were convex. The lateral border on either side presented six costal facets. Two distinct oval foramina were seen near the posterior border. Craniolateral processes were short and stump-like. Caudolateral processes fused with the median trabecula on either side. The rostrum was distinct. The morphological features of the sternum of Green-winged Macaw conformed to that of flying group of birds. It was almost similar to that of goose in its anterior half and to that of pigeon in its posterior half.

The patterns and synaptic properties of horizontal intracortical connections in the rat motor cortex

1993 ◽  
Vol 70 (4) ◽  
pp. 1553-1569 ◽  
Author(s):  
V. A. Aroniadou ◽  
A. Keller
Keyword(s):  
Motor Cortex ◽  
Deep Layer ◽  
Pyramidal Cells ◽  
Middle Layer ◽  
Synaptic Activity ◽  
Adult Rats ◽  
Retrograde Labeling ◽  
Connectivity Patterns ◽  
Layer V ◽  
Dendritic Fields

1. The laminar distribution of synaptic activity in the primary motor cortex, elicited by stimulation of intracortical, horizontal afferents, was studied in young (12-17 days old) and adult rats using the in vitro brain slice preparation. Connectivity patterns were deduced from current-source density (CSD) analyses of field potential depth profiles and were confirmed by anatomic data of retrograde cell labeling after focal injections of a fluorescent tracer. 2. According to the CSD distributions, horizontal axons in layer II/III provide strong monosynaptic input to dendrites of layer II and III pyramidal cells in a distant column, and weaker monosynaptic input to layer V and VI cells by synapsing on dendritic fields at the border of layer III and V and in deep layer V. When these pathways are activated, layer II/III cells may relay excitatory activity to upper and deep layer V, as well as to other cells in layer II/III of the same column. Axons arising from layer V provide monosynaptic input to pyramidal cells in all layers of neighboring columns, by synapsing in two dendritic fields: one in the superficial layers and the other in middle layer V. Activation of these pathways may generate a disynaptic intracolumnar input from layer II/III cells to middle layer V, as well as to other cells in layer II/III. Similar patterns of synaptic activity were elicited by stimulation from 0.45 to 2 mm distal to the recorded column. There were no apparent differences between young and adult rats in the connectivity patterns revealed by the CSD analyses. 3. Tracer injections in layer III resulted in retrograde labeling of cells in layers II/III and V, at distances > 2 mm from the injection site, whereas injections in layer V resulted in retrograde labeling of cells at long distances in layer V and to a lesser extent in layer II/III. These findings indicate that neurons in layer V project, via horizontal axon collaterals, for long distances within layers III and V, whereas the horizontal axon collaterals of layer III cells are restricted, for the most part, to the superficial layers. 4. Suppression of inhibitory activity by bath application of the gamma-aminobutyric acid-A (GABAA) receptor antagonist bicuculline methiodide (BMI) did not alter the pattern of the CSD distributions. All synaptic currents present in the control medium were enhanced by application of BMI, although the effect was more pronounced on the polysynaptic components.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals Lipoma of Tongue: a case report

2015 ◽  
Vol 14 (3) ◽  
pp. 302-304
Author(s):  
Morshed Asadullah Sikder ◽  
Mohibullah Mohibullah ◽  
Nahida Sultana
Keyword(s):  
Case Report ◽  
Benign Tumor ◽  
Medical Science ◽  
Ventral Surface ◽  
Anatomical Site ◽  
Fat Cell ◽  
Lateral Border ◽  
Tumor Excision ◽  
Complete Tumor

Lipoma is the benign tumor occurring at any anatomical site where fat is present. It may be evident for 1 to 5 percent of the entire benign tumor of the oral cavity. Lipoma of the tongue is extremely rare because tongue is totally devoid of fat cell. In this case study we report a case of lipoma of tongue. A 45 years old Bangladeshi female patient presented with this benign tumor at the left lateral border with dorsal and ventral surface of the tongue for which complete tumor excision was done.Bangladesh Journal of Medical Science Vol.14(3) 2015 p.302-304

scholarly journals The specifics of the implementation of the concept of “Antichrist” in the novel by D. S. Merezhkovsky “Peter and Alexey”

2021 ◽  
pp. 115-127
Author(s):  
Tatiana A. Neverova
Keyword(s):  
Outer Layer ◽  
Deep Layer ◽  
Middle Layer ◽  
Frame Structure ◽  
Early 20Th Century ◽  
Distributional Analysis ◽  
The Novel ◽  
The Third ◽  
John The Baptist

The article is devoted to the study of the concept of “Antichrist” in the language picture of the world by D. S. Merezhkovsky. The relevance of the study is due to the significant role of the writer in the literature of the late 19th-early 20th century and the dominance of religious and philosophical ideas in his work. The work is aimed at identifying the specifics of the implementation of the concept of “Antichrist” as one of the key concepts for D.S. Merezhkovsky, analyzing its structure and main representations. The material for the study was the text of the novel “Peter and Alexey”, which was studied using the methods of component, frame and distributional analysis. The paper considers three layers of the concept: the outer layer, which corresponds to the biblical text and represents an literary reconstruction of the eschatological popular consciousness of the 23th and 18th centuries, the middle layer, which contains the idea of Peter as the Antichrist, and the deep layer, formed by the idea of the Antichrist as an entity inextricably linked with Christ in the struggle and unity at the same time. As a result of comparison with one of the first texts that allows us to reconstruct this concept, the Revelation of St. John the Baptist. The differentiating features that make up the peculiarity of the implementation of the concept of “Antichrist” in the text under study are highlighted. It is determined that the outer layer of the concept has a frame structure, and the slots included in it are identified. The semes included in the middle layer of the concept, which has a field structure, are analyzed, the organizing dominant and distributional connections between individual semes are established, which allow combining them into hypersemes. The togetherness of the signification in the third, deep layer of the concept of “Antichrist’s beginning” and “Christ’s beginning” is revealed, which is especially clearly manifested in the fragments that have a mystical character. Based on the analysis of the concept of “Antichrist”, which is widely and variously represented in the text of the novel” Peter and Alexey”, the author concludes that it affects the text and the system of images.

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