Interactions de l'œil et du lobe optique au cours de la croissance post-embryonnaire des Insectes odonates

Development ◽  
1974 ◽  
Vol 31 (2) ◽  
pp. 377-407
Author(s):  
Par Michel Mouze
Keyword(s):  
Optic Lobe ◽  
Ganglion Cells ◽  
Final Position ◽  
Regulatory Effect ◽  
Nerve Fibres ◽  
Isolated Organs ◽  
Mitogenic Action ◽  
Different Types

Different types of experiments have been performed in order to disturb or to destroy the relations between the eye and the optic lobe and then to study these isolated organs. The results show that growth and differentiation of the eye is independent of the optic lobe. However, the structure of ommatidia whose post-retinal fibres have been sectioned is markedly modified. The growth of the optic lobe is closely related to the presence of the eye and more precisely to the connexion with the post-retinal fibres. The volume of the optic lobe, especially the more external optic ganglia, is reduced after its relations with the eye are disturbed. Moreover numerous abnormalities in its structure evince a disordered organization of new nerve fibres, which are attracted by the newly constituted zone of the lamina and exert a mitogenic action on the outer growing zone of the optic lobe. These fibres seem to exert a regulatory effect upon the differentiation and final position of the new ganglion cells.

The Dogfish Neuromuscular Junction: Dual Innervation of Vertebrate Striated Muscle Fibres?

1972 ◽  
Vol 10 (3) ◽  
pp. 657-665
Author(s):  
Q. BONE
Keyword(s):  
Neuromuscular Junction ◽  
Nerve Terminal ◽  
Striated Muscle ◽  
Dense Core ◽  
The Other ◽  
Muscle Fibres ◽  
Nerve Terminals ◽  
Nerve Fibres ◽  
Different Types ◽  
Motor End Plate

In the myotomal muscles of the dogfish, Scyliorhinu canicula, there are 2 major types of fibre. The red fibres at the periphery of the myotome receive a distributed en grappe pattern of innervation. There are subjunctional folds at these endings, and the nerve terminals contain vesicles around 50 nm in diameter. In contrast to this, the white twitch fibres of the myotome are innervated focally, by 2 nerve fibres passing to the same motor end-plate. These 2 fibres contain vesicles of different types. One type of nerve terminal contains vesicles around 50 nm in diameter; these terminals resemble those upon the red fibres. The other contains vesicles up to 100 nm in diameter, frequently possessing a dense core. It is suggested that the white twitch fibres of dogfish are innervated by 2 separate axons, possibly containing different transmitter substances.

The role of the nervous system in smooth muscle contraction in anaphylaxis

1937 ◽  
Vol 33 (7) ◽  
pp. 899-904
Author(s):  
A. N. Gordienko
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Anaphylactic Shock ◽  
Ganglion Cells ◽  
Dominant Role ◽  
Smooth Muscles ◽  
Smooth Muscle Contraction ◽  
Central System ◽  
Autonomic Nervous ◽  
Isolated Organs

The problem of the participation of the nervous system in the pathogenesis of anaphylactic shock has been the focus of attention of many researchers. Despite the large number of works, a consensus on this issue has not yet been reached. It is known that isolated organs of a sensitized animal can react to an antigen much more strongly than organs of a non-sensitized animal. By isolating the uterus, a piece of intestine, etc., we separate the latter from the central system and by this we judge that an anaphylactic reaction can proceed without the participation of the nervous system. At the same time, we forget two provisions: first, that the reaction of smooth muscles in isolated conditions differs in many respects from the reaction of the whole organism and, second, that these isolated organs contain elements of the autonomic nervous system in the form of fibers and nerve endings and peripheral ganglion cells. Therefore, we believe that the data obtained on isolated organs cannot serve as evidence of the passivity of the autonomic nervous system in anaphylactic shock, the participation of the latter should be studied on the whole organism. We have published our experimental data on the participation of the nervous system in the pathogenesis of anaphylactic shock. In this work, we tried to establish the importance of the nervous system in the reaction of smooth muscles in the whole organism, which is given a dominant role in the pathogenesis of anaphylactic shock.

The innervation of the frog’s heart I. An examination of the autonomic postganglionic nerve fibres and a comparison of autonomic and sensory ganglion cells

1970 ◽  
Vol 176 (1042) ◽  
pp. 43-54 ◽  
Keyword(s):  
Silver Staining ◽  
Ganglion Cells ◽  
Sympathetic Ganglia ◽  
Sensory Ganglion ◽  
Nerve Fibres ◽  
Dense Networks ◽  
Histochemical Methods ◽  
Muscle Innervation ◽  
Motor Cells ◽  
Postganglionic Nerve

The pattern of innervation in the frog’s heart shown by silver staining has been compared with the results of histochemical methods. The muscle innervation is a series of dense networks of nerve bundles. These have been divided into four groups according to their size and distribution. The silver methods show fewer fibres than the histochemical methods but all the methods show the same distribution of fibres. The ganglion cells in the vagal, dorsal root and sympathetic ganglia, and in the vagosympathetic trunks and heart, have been examined with silver staining and histochemical methods. It has been concluded that the vagal ganglion cells are probably sensory; that the sympathetic ganglion cells are confined to the sympathetic chain; and that all the cells in the vagosympathetic trunks and heart are parasympathetic motor cells. Section of the vagosympathetic trunks causes loss of all fluorescent nerve fibres from the heart, while at the sametime there are no changes in the distribution of acetylcholinesterase-containing fibres in the muscle. It is concluded that the fluorescence and acetylcholinesterase methods show respectively the sympathetic and parasympathetic postganglionic fibres. There is no evidence from this work to support the claims that some recently described and extensive plexuses of fibres on the muscle are in fact nervous in origin.

A quantitative analysis of the effects of excitatory neurotoxins on retinal ganglion cells in the chick

1990 ◽  
Vol 4 (3) ◽  
pp. 217-223 ◽  
Author(s):  
Ngoh Ngoh Tung ◽  
Ian G. Morgan ◽  
David Ehrlich
Keyword(s):  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Amacrine Cells ◽  
Small Cells ◽  
Retinal Ganglion ◽  
Chick Retina ◽  
Area 5 ◽  
Different Types ◽  
Displaced Amacrine Cells ◽  
Series Of Experiments

AbstractThe present study examines the differential effects of three excitotoxins, kainic acid (KA), N-methyl-D-aspartate (NMDA), and α-amino-2,3-amino-2,3-dihydro-5- methyl-3-oxo-4- isoxazolepropanoic acid (AMPA) on neurons within the genglion cell layer (GCL) of the chick retina. Two-day-old chicks were given a single, 5 μl, intravitreal injection of KA, NMDA, or AMPA at a range of doses. Following treatment with 40 nmol KA, there was a 21% loss of neurons in the GCL. At 200 nmol KA, the loss increased to 46%. Exposure to KA eliminated mainly small neurons of soma area 5–15μm2, and medium-sized ganglion cells of soma area 15–25μm2. Large ganglion cells (>25μ,2) remained unaffected. The vast majority of small cells were probably displaced amarcrine cells. At a does of 3000 nmol NMDA, no further loss of cells was evident. Exposure to 200 nmol AMPA resulted in a 30% loss of large and some medium-sized ganglion cells. In a further series of experiments, exposure to excitotoxin was followed by a retinal scratch, which eliminated retinal ganglion cells within the axotomized region. The results indicate that only a small proportion of displaced amacrine cells are destroyed by NMDA and AMPA, whereas virtually all displaced amarine cells are sensitive to KA. The findings of this study indicate the existence of subclasses of ganglion cells with specificity towards different types of excitatory amino acids (EAA).

Clause-final negation

2003 ◽  
Vol 9 (2) ◽  
pp. 239-268 ◽  
Author(s):  
Ger P. Reesink
Keyword(s):  
Final Position ◽  
Different Types ◽  
Structural Levels ◽  
Sentential Operator ◽  
Negative Adverb

Negation in a number of Austronesian and Papuan languages with SVO order is expressed by a rather rigid clause-final position of the negative adverb. Some typological generalizations for negation are reviewed and the distribution of this trait in languages of different stocks is discussed, arguing that it most likely originates in Papuan languages. Some proposals for different types of negation, such as whether it is a verbal (or VP) operator, a constituent operator or a sentential operator are considered. The problem of determining the scope of negation is discussed, with the conclusion that hard and fast semantic meanings for NEG at different structural levels cannot be posited, suggesting that perhaps a solution can be found in the application of some universal pragmatic principles.

The optic lobes of Octopus vulgaris

1962 ◽  
Vol 245 (718) ◽  
pp. 19-58 ◽  
Keyword(s):  
Optic Nerve ◽  
Optic Lobe ◽  
Optic Tract ◽  
Amacrine Cells ◽  
Visual Input ◽  
Octopus Vulgaris ◽  
Coding System ◽  
Nerve Fibres ◽  
Dendritic Trees ◽  
Optic Lobes

The optic lobes provide a system for coding the visual input, for storing a record of it and for decoding to produce particular motor responses. There are at least three types of optic nerve fibre, ending at different depths in the layered dendritic systems of the plexiform zone. Here the optic nerve fibres meet the branches of at least four types of cell. (1) Centripetal cells passing excitation inwards. The dendrites of these are very long, with fields orientated more often in horizontal and vertical than in other directions. (2) Numerous amacrine cells, with cone-shaped dendritic fields but no determinable axon. (3) Centrifugal cells conducting back to the retina. (4) Commissural fibres from the opposite optic lobe, and other afferents. After section of the optic nerves the plexiform layer of the corresponding part of the optic lobe becomes reduced, but the tangential layers of dendrites remain. There is a reduction in the thickness of the layers of amacrine and other cells and a shrinkage of the whole lobe. Conversely the tangential layers can be degenerated, leaving the optic nerve fibres, by severing the arteries to the optic lobe. The centre of the optic lobe contains cells with spreading dendritic trees of many forms. Some run mainly tangentially, others are radial cones. Those towards the centre send axons to the optic tract. Small multipolar cells accompany the large neurons of the cell islands. About 2 x 10 7 optic nerve fibres visible with the light microscope enter the lobes but only 0-5 x 106, or less, leave in the optic tract, these being distributed to some ten centres in the supraoesophageal lobes. It is suggested that the variety of shapes of the dendritic trees within the optic lobes provides the elements of the coding system by which visual input is classified.

scholarly journals Animal Models of Glaucoma

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Rachida A. Bouhenni ◽  
Jeffrey Dunmire ◽  
Abby Sewell ◽  
Deepak P. Edward
Keyword(s):  
Optic Nerve ◽  
Animal Models ◽  
Visual Impairment ◽  
Retinal Ganglion Cells ◽  
Ganglion Cells ◽  
Suitable Model ◽  
Retinal Ganglion ◽  
Ideal Model ◽  
Different Types ◽  
Pathophysiologic Mechanisms

Glaucoma is a heterogeneous group of disorders that progressively lead to blindness due to loss of retinal ganglion cells and damage to the optic nerve. It is a leading cause of blindness and visual impairment worldwide. Although research in the field of glaucoma is substantial, the pathophysiologic mechanisms causing the disease are not completely understood. A wide variety of animal models have been used to study glaucoma. These include monkeys, dogs, cats, rodents, and several other species. Although these models have provided valuable information about the disease, there is still no ideal model for studying glaucoma due to its complexity. In this paper we present a summary of most of the animal models that have been developed and used for the study of the different types of glaucoma, the strengths and limitations associated with each species use, and some potential criteria to develop a suitable model.

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