scholarly journals Morphological study of the midbrain tectum in ostrich (Struthio camelus) embryo

2019 ◽  
Vol 22 (2) ◽  
pp. 143-151
Author(s):  
Z. Koushafar ◽  
A. Mohammadpour
Keyword(s):  
Optic Tectum ◽  
Morphological Study ◽  
Optic Lobe ◽  
Molecular Layer ◽  
Anatomical Study ◽  
Ependymal Cells ◽  
Paraffin Sections ◽  
Optic Lobes ◽  
Ventricle Volume ◽  
Ostrich Embryo

In this study the morphological features of the optic tectum in ostrich embryo were studied macroscopically and microscopically. After gross anatomical study, fixed specimens of the optic lobes in 30th, 36th and 40th embryonic days were processed for paraffin sections. Sections were stained by Harris haematoxylin and eosin (H&E), Luxol Fast Blue/Cresyl Echt Violet and Malory PTAH dyes. The optic lobes had large volumes even on the 30th embryonic day and increased proportionally to age. The optic lobe consisted of two parts: gray matter (outer) and white matter (inner). The first external layer of the optic lobe e.g. molecular layer consisted of neural fibres, neuroglia and scarce small neurons. The most common appearance of the optic lobes was characterised by small to medium-sized neurons (rounded to pyramid-shaped with large and pale nucleus consistong of obvious nucleoli arranged in three layers whose thickness increased in the deeper one) supported by neuroglia. Larger size neurons and occasionally multipolar neurons were presented in the interior compared with these layers. The lateral mesencephalic nucleus was detectable in the optic lobe base even on 30th embryonic day and was composed of few multipolar neurons supported by neuroglia. The tectal ventricles were lined with simple cuboidal ciliated ependymal cells in the embryonic period. As embryonic age increased, the ratio of tectal ventricle volume to its thickness decreased. Special stainings showed that Nissl bodies and myelin fibres, also glial fibres were available from the 30th embryonic day and that their density, especially myelin fibres density, increased with age.

scholarly journals Immunoistochemical and morphological study of periodont tissues when predicting the results of dental implantation in patients with chronic parodontitis

2019 ◽  
Vol 488 (4) ◽  
pp. 452-456
Author(s):  
A. A. Kulakov ◽  
E. A. Kogan ◽  
T. V. Brailovskaya ◽  
A. P. Vedyaeva ◽  
N. V. Zharkov
Keyword(s):  
Proliferative Activity ◽  
Morphological Study ◽  
Immunohistochemical Study ◽  
Additional Treatment ◽  
Paraffin Sections ◽  
Regenerative Capacity ◽  
Ki 67 ◽  
Dental Implantation ◽  
Growth Zones ◽  
Severe Degree

A morphological and immunohistochemical study of 24 gums biopsies was conducted in 19 patients aged 35-60 years with a diagnosis of partial secondary edentulous, chronic generalized periodontitis of moderate and severe degree (14 patients), and also without pathological changes in the periodontal disease (5 patients), who underwent dental implantation. Immunohistochemical reactions with antibodies to Ki-67, VEGF, SMA were performed on serial paraffin sections. It has been established that chronic periodontitis is characterized by a higher proliferative activity of the epithelium, which reflects its hyperplastic changes, as well as a lower content of SMA positive cells and the practical absence of the formation of privascular couplings from SMA-positive cells that are associated in tissues with growth zones, which indirectly indicates reduced tissue regenerative capacity. Therefore, in the case of the operation of dental implantation requires additional treatment aimed at anti-inflammatory and pro-regenerative effects.

Electron microscopy of optic nerves and optic lobes of Octopus and Eledone

1963 ◽  
Vol 158 (973) ◽  
pp. 446-456 ◽  
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Optic Nerve ◽  
Schwann Cells ◽  
Synaptic Vesicles ◽  
Optic Lobe ◽  
Granule Cells ◽  
Proximal Region ◽  
Optic Lobes ◽  
Optic Axons

Each optic nerve contains several bundles of axons. The axons have their surface membranes directly apposed and the bundles lie in troughs of the elongated Schwann cells. The axons have pronounced varicosities along their length. The axons enter the optic lobe and run between the granule cells to synapse in the plexiform zone. The granule cells are small neurons. Their cytoplasmic organelles include endoplasmic reticulum, ribosomes, agranular reticulum and of special interest, oval or spherical bodies with a lamellated cortex and granular medulla. The elongated varicose presynaptic bags of the optic axons contain mitochondria in the proximal region, numerous synaptic vesicles and, sometimes, neurofilaments. Below the mitochondrial zone, synaptic contacts are made with small spines invaginated into the bags. The spines probably originate from the trunks of the granule cells. Tunnel fibres that are probably trunks of the outer granule cells, run through channels in the synaptic bags.

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.

A memory system in Octopus vulgaris Lamarck

1955 ◽  
Vol 143 (913) ◽  
pp. 449-480 ◽  
Keyword(s):  
Optic Lobe ◽  
Complete Removal ◽  
Frontal Lobes ◽  
Octopus Vulgaris ◽  
Partial Removal ◽  
Retinal Surface ◽  
Optic Lobes ◽  
Neural Activities ◽  
Inhibitory Region ◽  
Set Up

An octopus that has attacked a crab shown with a square and received a shock rapidly learns not to attack when this situation appears again, while continuing to attack crabs shown alone. The memory preventing attack on crabs shown with a white square may last for 2 or 3 days if the crab and square are not shown during that period. If the situation is shown three times a day the memory may last for 6 days or longer. The memory is not erased by anaesthesia nor by electrical stimulation of the supra-oesophageal lobes. After complete removal of the vertical lobe, or of the medial superior frontal lobe, or section of the tract between the two, the memory preventing attack is lost and cannot again be acquired. Animals operated in this way attack a crab and square if shown at 2-hourly intervals in spite of the numerous shocks they receive. A transitory memory lasting a few minutes can still be set up if the frequency of presentation is increased to about once every 5 min. Partial removal of the vertical lobe system does not interrupt the memory. A memory set up by the use of one eye is not abolished if the optic lobe of that side is later removed. The memory is not interrupted by slashes in both optic lobes. After lesions to the lateral parts of the superior frontal lobes an octopus makes few or no further attacks on crabs, unless these are placed close to the animal. The effect of such an operation is to upset the balance of central neural activities in such a way that a region responsible for inhibiting attacks on distant objects assumes control. This inhibitory region may be the first subvertical lobe, whose action is normally balanced by the lateral superior frontal lobes and the vertical lobe. The tangle of fibre bundles within the optic lobes allows for a wide degree of interaction between impulses arriving from different parts of the retinal surface. In addition, these lobes receive afferent fibres from the arms. They thus provide a system within which associations between given sets of inputs can be set up in such a way as to ensure that there is no attack when a similar set of inputs occurs again. Further plexiform arrangements are found in the pathway from the optic to the superior frontal lobes and from the latter to the vertical lobe. These plexuses make possible the interaction in each succeeding lobe of impulses arriving from distant parts of the preceding lobe. Each lobe can thus serve to record the pattern of associations present in the previous one. Since the arrangement is circular the pattern originating in the optic lobe is then re-presented back to it. It is suggested that the vertical lobe system serves to prolong memories set up in the optic lobes by re-presenting them from within, and thus allowing them to persist for long enough to produce some change of a more permanent nature.

scholarly journals Strange eyes, stranger brains: exceptional diversity of optic lobe organization in midwater crustaceans

2021 ◽  
Vol 288 (1948) ◽  
Author(s):  
Chan Lin ◽  
Henk-Jan T. Hoving ◽  
Thomas W. Cronin ◽  
Karen J. Osborn
Keyword(s):  
Optic Lobe ◽  
Molecular Level ◽  
Brain Evolution ◽  
Brain Regions ◽  
Divergent Evolution ◽  
Ground Pattern ◽  
Optic Lobes ◽  
Trade Offs ◽  
The Central Nervous System ◽  
Diverse Groups

Nervous systems across Animalia not only share a common blueprint at the biophysical and molecular level, but even between diverse groups of animals the structure and neuronal organization of several brain regions are strikingly conserved. Despite variation in the morphology and complexity of eyes across malacostracan crustaceans, many studies have shown that the organization of malacostracan optic lobes is highly conserved. Here, we report results of divergent evolution to this ‘neural ground pattern’ discovered in hyperiid amphipods, a relatively small group of holopelagic malacostracan crustaceans that possess an unusually wide diversity of compound eyes. We show that the structure and organization of hyperiid optic lobes has not only diverged from the malacostracan ground pattern, but is also highly variable between closely related genera. Our findings demonstrate a variety of trade-offs between sensory systems of hyperiids and even within the visual system alone, thus providing evidence that selection has modified individual components of the central nervous system to generate distinct combinations of visual centres in the hyperiid optic lobes. Our results provide new insights into the patterns of brain evolution among animals that live under extreme conditions.

scholarly journals Preliminary morphological and anatomical study of Orthosiphon stamineus

2013 ◽  
Vol 1 (04) ◽  
pp. 01-06 ◽  
Author(s):  
Manaf Almatar ◽  
Zaidah Rahmat ◽  
Faezah Mohd Salleh
Keyword(s):  
Medicinal Plant ◽  
Cross Sections ◽  
Morphological Study ◽  
Developmental Stages ◽  
Anatomical Study ◽  
Medical Application ◽  
Orthosiphon Stamineus ◽  
Phenolics Compounds ◽  
Wide Usage

This study focuses on the characterization of morphological and anatomical traits of Orthosiphon stamineus which belongs to the Lamiaceae family. Orthosiphon stamineus, better known as “Misai Kucing” or “cats whiskers” by the locals, contained active phenolics compounds such as flavanoids. Despite its wide usage as a medicinal plant, information regarding Orthosiphon stamineus specific developmental stages is relatively scarce. Furthermore, to date, no anatomical data of this plant is available. Therefore, this study aims to systematically identify the developmental stages and its anatomy which may provide more insight to its medical application. The result showed some distinct morphological and anatomical characteristics. In the morphological study, it was observed that Orthosiphon stamineus is a herbal shrub with well-developed creeping rootstock. The leaves are simple, green, and arranged in opposite pairs. The stem is approximately 28 cm in height at the stage (12 days). The flowers have long wispy stamens shaped with pale purple color. In anatomical study, the cross sections of the stem for tow stage (32) and (62) days of this plant were examined. All the detailed systematic study of this plant has not worked earlier.

scholarly journals Morphological Study on the Fibula in Japanese: Basic Anatomical Study for Maxillofacial Reconstruction

2018 ◽  
Vol 27 (4) ◽  
pp. 287-294
Author(s):  
Hidetomo Hirouchi ◽  
Yoshiaki Shimoo ◽  
Masashi Suzuki ◽  
Satoru Matsunaga ◽  
Masahito Yamamoto ◽  
...  
Keyword(s):  
Morphological Study ◽  
Anatomical Study ◽  
Maxillofacial Reconstruction

Identified octopaminergic neurons provide an arousal mechanism in the locust brain

1995 ◽  
Vol 74 (6) ◽  
pp. 2739-2743 ◽  
Author(s):  
J. P. Bacon ◽  
K. S. Thompson ◽  
M. Stern
Keyword(s):  
Action Potentials ◽  
Tactile Stimulation ◽  
Neural Circuit ◽  
Optic Lobe ◽  
Repetitive Stimulation ◽  
Movement Detector ◽  
Optic Lobes ◽  
Tactile Stimuli ◽  
Arousal Mechanism ◽  
Contralateral Movement

1. Habituation is the declining responsiveness of a neural circuit (or behavior) to repetitive stimulation. Dishabituation (or arousal) can be brought about by the sudden presentation of an additional, novel stimulus. A clear example of arousal in the locust is provided by the visual system: the habituated response of the descending contralateral movement detector (DCMD) interneuron to repetitive visual stimuli can be dishabituated by a variety of other visual and tactile stimuli. 2. Application of octopamine to the locust brain and optic lobes dishabituates the DCMD in a manner similar to the effect of visual and tactile stimulation. 3. The locust CNS contains two pairs of octopamine-immunoreactive cells, the protocerebral medulla 4 (PM4) neurons, that could potentially mediate this dishabituation effect; PM4 neurons arborize in the optic lobe, they contain octopamine, and they respond to the same visual and tactile stimuli that dishabituate the DCMD. 4. To investigate whether PM4 activity dishabituates the DCMD, we recorded intracellularly from one of the PM4 neurons while recording extracellularly from the DCMD. When the PM4 neuron is injected with hyperpolarizing current to render it completely inactive, the DCMD exhibits its characteristic habituation to a moving visual stimulus. However, depolarizing the PM4 neuron, to produce action potentials at approximately 20 Hz, significantly increases the number of DCMD action potentials per stimulus. 5. The PM4 neurons may therefore play an important role in dishabituating the DCMD to novel stimuli. This effect is presumably mediated by PM4 neurons releasing endogenous octopamine within the optic lobe.

Golgi studies on insects Part I. The optic lobes of Lepidoptera

1970 ◽  
Vol 258 (820) ◽  
pp. 81-134 ◽  
Keyword(s):  
Optic Lobe ◽  
Amacrine Cells ◽  
Class I ◽  
Small Field ◽  
Class Iii ◽  
Optic Lobes ◽  
Visual Cells ◽  
Pass Through ◽  
Parallel Arrays ◽  
I Cells

Variants of the Golgi-Colonnier (1964) selective silver procedure have been used to show up neurons in insect brains. Neural elements are particularly clearly impregnated in the optic lobes. Three classes of nerve cells can be distinguished; perpendicular (class I), tangential (class II) and amacrine cells (class III). There are m any types of neurons in each class which together have a very wide variety of form. Their components are related to specific strata in the optic lobe regions. Short visual cells from the retina terminate in the lamina in discrete groups of endings (optic cartridges). Pairs of long visual fibres from ommatidia pass through the lamina and end in the medulla. Class I cells link these two regions in parallel with the long visual fibres and groups of these elements define columns in the medulla. These in turn give rise to small-field fibres that project to the lobula complex. Tangential processes intersect the parallel arrays of class I cells at characteristic levels. Some are complex in form and may invade up to three regions. Another type provides a direct link between the ipsi- and contralateral optic lobe. Amacrine cells are intrinsic to single lobe regions and have processes situated at the same levels as those of classes I and II cells. A fifth optic lobe region, the optic tubercle, is connected to the medulla and lobula and also receives a set of processes from the mid-brain. There are at least six separate types of small-field relays which could represent the retina mosaic arrangement in the lobula.

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