Principles of Current Vertebrate Neuromorphology

2017 ◽  
Vol 90 (2) ◽  
pp. 117-130 ◽  
Author(s):  
Rudolf Nieuwenhuys ◽  
R. Nieuwenhuys
Keyword(s):  
Cellular Proliferation ◽  
Three Dimensional ◽  
Checkerboard Pattern ◽  
Tangential Migration ◽  
Molecular Patterning ◽  
The Central Nervous System ◽  
Cartesian Coordinate ◽  
Transverse Patterning ◽  
Further Development ◽  
The Brain

Causal analysis of molecular patterning at neural plate and early neural tube stages has shown that the central nervous system (CNS) of vertebrates is essentially organized into transverse neural segments or neuromeres and longitudinal zones which follow the curved axis of the brain. The intersection of the longitudinal and transverse patterning processes in the embryonic brain leads to the formation of a checkerboard pattern of distinct progenitor domains called “fundamental morphological units” (FMUs). The topologically invariant pattern formed by the ventricular surfaces of the FMUs of a given taxon represents the “Bauplan” or “blueprint” of the brain of that taxon. The FMUs initially represent thin epithelial fields; during further development they are transformed into three-dimensional radial units, extending from the ventricular surface to the meningeal surface. It is of note that the boundaries of the neuromeres, longitudinal zones, and radial units all strictly adhere to a non-Cartesian coordinate system inherent to the CNS of all vertebrates. The major neural histogenetic processes, including cellular proliferation, radial migration, and differentiation, as well as the formation of grisea (cell masses, nuclei, and cortices), occur principally within the confines of the FMUs, although tangential migration may also take cells to distant sites. Hence, recognition and delimitation of these units is essential for the identification and interpretation of grisea. An outline of the procedure to be followed in these processes of identification and interpretation is presented, and a list of the pertinent homology criteria is provided.

Experiments on Neuromery in Ambystoma punctatum Embryos

Development ◽  
1956 ◽  
Vol 4 (1) ◽  
pp. 66-72
Author(s):  
Bengt Källén
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mitotic Activity ◽  
Present Author ◽  
Similar Nature ◽  
High Mitotic Activity ◽  
The Central Nervous System ◽  
Further Development ◽  
The Brain ◽  
Low Activity

In a series of papers the present author has discussed the nature and significance of the transverse bulges of the central nervous system of vertebrates, long since known as neuromeres. Their formation and further development have been described and it has been shown that they are signs of a proliferation pattern, made up of transverse bands of high mitotic activity alternating with bands of low activity. It has also been demonstrated that the neuromeric pattern is preceded by another pattern of a similar nature, mirrored in the formation of the so-called proneuromeres, and is followed by a third pattern, giving rise to the postneuromeres or transverse bands of migration areas. For further details of these investigations, the reader is referred to Bergquist & Källén (1954). An unsolved question is the nature of the factors that cause the patterning of the mitoses and therefore also the bulging of the brain wall to form neuromeres.

A Mechanical Model of Hand Force in Power Hand Tool Operation

1995 ◽  
Vol 39 (10) ◽  
pp. 548-552 ◽  
Author(s):  
Robert G. Radwin ◽  
Seoungyeon Oh ◽  
Frank J. Fronczak
Keyword(s):  
Mechanical Model ◽  
Three Dimensional ◽  
Physical Parameters ◽  
Power Grip ◽  
Feed Force ◽  
Hand Tool ◽  
Hand Force ◽  
Cartesian Coordinate ◽  
Development And Validation ◽  
Further Development

A three-dimensional static equilibrium mechanical model of power hand tool operation was developed and used for comparing hand force associated with use of nutrunners having similar operating parameters (i.e. torque and feed force) but different physical parameters (i.e. shape, size, and mass distribution). The model used a Cartesian coordinate system relative to the orientation of the handle grasped in the hand using a power grip. Several important relationships between tool parameters and required hand force were revealed. Resultant hand force associated with different torque and feed force requirements were compared between four pistol grip nutrunners, and between pistol grip and right angle tools used for the same operation. Accessory handles and counterbalancers are also included in the model. Further development and validation of this model will be useful to power hand tool designers and tool engineers.

scholarly journals Internal structure of the cerebral hemispheres: an introduction of fiber dissection technique

2005 ◽  
Vol 63 (2a) ◽  
pp. 252-258 ◽  
Author(s):  
Igor de Castro ◽  
Daniel de Holanda Christoph ◽  
Daniel Paes dos Santos ◽  
José Alberto Landeiro
Keyword(s):  
Three Dimensional ◽  
Medial Aspect ◽  
Lateral Aspect ◽  
Critical Pathways ◽  
Brain Hemispheres ◽  
The Central Nervous System ◽  
Fiber Dissection ◽  
Dissection Technique ◽  
The Brain ◽  
Neuroimaging Techniques

The aim of this study is to introduce the fiber dissection technique and its importance in the comprehension of the three-dimensional intrinsic anatomy of the brain. A total of twenty brain hemispheres were dissected. Using Kingler's technique we demonstrated the intrinsic structures of the brain. The supra lateral aspect of the brain as well as the medial aspect were presented. The most important fiber systems were demonstrated. The use and comprehension of new neuroimaging techniques demand a better understanding of this fascinating anatomy. The knowledge acquired with this technique will improve our understanding of critical pathways of the central nervous system.

scholarly journals Fundamentals of the modern theory of the phenomenon of "pain" from the perspective of a systematic approach. Neurophysiological basis. Part 1: A brief presentation of key subcellular and cellular ctructural elements of the central nervous system.

Pain medicine ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 6-40 ◽  
Author(s):  
V I Poberezhnyi ◽  
O V Marchuk ◽  
O S Shvidyuk ◽  
I Y Petrik ◽  
O S Logvinov
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Functional Organization ◽  
Three Dimensional ◽  
Synaptic Connections ◽  
Nerve Impulses ◽  
Short Period ◽  
The Central Nervous System ◽  
The Brain ◽  
Computational Properties

The phenomenon of “pain” is a psychophysiological phenomenon that is actualized in the mind of a person as a result of the systemic response of his body to certain external and internal stimuli. The heart of the corresponding mental processes is certain neurophysiological processes, which in turn are caused by a certain form of the systemic structural and functional organization of the central nervous system (CNS). Thus, the systemic structural and functional organization of the central nervous system of a person, determining the corresponding psychophysiological state in a specific time interval, determines its psycho-emotional states or reactions manifested by the pain phenomenon. The nervous system of the human body has a hierarchical structure and is a morphologically and functionally complete set of different, interconnected, nervous and structural formations. The basis of the structural formations of the nervous system is nervous tissue. It is a system of interconnected differentials of nerve cells, neuroglia and glial macrophages, providing specific functions of perception of stimulation, excitation, generation of nerve impulses and its transmission. The neuron and each of its compartments (spines, dendrites, catfish, axon) is an autonomous, plastic, active, structural formation with complex computational properties. One of them – dendrites – plays a key role in the integration and processing of information. Dendrites, due to their morphology, provide neurons with unique electrical and plastic properties and cause variations in their computational properties. The morphology of dendrites: 1) determines – a) the number and type of contacts that a particular neuron can form with other neurons; b) the complexity, diversity of its functions; c) its computational operations; 2) determines – a) variations in the computational properties of a neuron (variations of the discharges between bursts and regular forms of pulsation); b) back distribution of action potentials. Dendritic spines can form synaptic connection – one of the main factors for increasing the diversity of forms of synaptic connections of neurons. Their volume and shape can change over a short period of time, and they can rotate in space, appear and disappear by themselves. Spines play a key role in selectively changing the strength of synaptic connections during the memorization and learning process. Glial cells are active participants in diffuse transmission of nerve impulses in the brain. Astrocytes form a three-dimensional, functionally “syncytia-like” formation, inside of which there are neurons, thus causing their specific microenvironment. They and neurons are structurally and functionally interconnected, based on which their permanent interaction occurs. Oligodendrocytes provide conditions for the generation and transmission of nerve impulses along the processes of neurons and play a significant role in the processes of their excitation and inhibition. Microglial cells play an important role in the formation of the brain, especially in the formation and maintenance of synapses. Thus, the CNS should be considered as a single, functionally “syncytia-like”, structural entity. Because the three-dimensional distribution of dendritic branches in space is important for determining the type of information that goes to a neuron, it is necessary to consider the three-dimensionality of their structure when analyzing the implementation of their functions.

scholarly journals Mathematical modeling of therapeutic neural stem cell migration in mouse brain with and without brain tumors

2022 ◽  
Vol 19 (3) ◽  
pp. 2592-2615
Author(s):  
Justin Gomez ◽  
◽  
Nathanael Holmes ◽  
Austin Hansen ◽  
Vikram Adhikarla ◽  
...  
Keyword(s):  
Brain Tumors ◽  
Mouse Brain ◽  
Low Cost ◽  
Three Dimensional ◽  
Intracerebral Injection ◽  
Tumor Site ◽  
Stem Cell Migration ◽  
Proposed Model ◽  
The Central Nervous System ◽  
The Brain

<abstract><p>Neural stem cells (NSCs) offer a potential solution to treating brain tumors. This is because NSCs can circumvent the blood-brain barrier and migrate to areas of damage in the central nervous system, including tumors, stroke, and wound injuries. However, for successful clinical application of NSC treatment, a sufficient number of viable cells must reach the diseased or damaged area(s) in the brain, and evidence suggests that it may be affected by the paths the NSCs take through the brain, as well as the locations of tumors. To study the NSC migration in brain, we develop a mathematical model of therapeutic NSC migration towards brain tumor, that provides a low cost platform to investigate NSC treatment efficacy. Our model is an extension of the model developed in Rockne et al. (PLoS ONE 13, e0199967, 2018) that considers NSC migration in non-tumor bearing naive mouse brain. Here we modify the model in Rockne et al. in three ways: (i) we consider three-dimensional mouse brain geometry, (ii) we add chemotaxis to model the tumor-tropic nature of NSCs into tumor sites, and (iii) we model stochasticity of migration speed and chemosensitivity. The proposed model is used to study migration patterns of NSCs to sites of tumors for different injection strategies, in particular, intranasal and intracerebral delivery. We observe that intracerebral injection results in more NSCs arriving at the tumor site(s), but the relative fraction of NSCs depends on the location of injection relative to the target site(s). On the other hand, intranasal injection results in fewer NSCs at the tumor site, but yields a more even distribution of NSCs within and around the target tumor site(s).</p></abstract>

scholarly journals Brain Ultrastructure: Putting the Pieces Together

2021 ◽  
Vol 9 ◽  
Author(s):  
Patrick C. Nahirney ◽  
Marie-Eve Tremblay
Keyword(s):  
Three Dimensional ◽  
Cell Types ◽  
Brain Parenchyma ◽  
Electron Microscopic ◽  
Functional Relationships ◽  
Resolution Electron ◽  
The Central Nervous System ◽  
Cytoskeletal Elements ◽  
Different Cell Types ◽  
The Brain

Unraveling the fine structure of the brain is important to provide a better understanding of its normal and abnormal functioning. Application of high-resolution electron microscopic techniques gives us an unprecedented opportunity to discern details of the brain parenchyma at nanoscale resolution, although identifying different cell types and their unique features in two-dimensional, or three-dimensional images, remains a challenge even to experts in the field. This article provides insights into how to identify the different cell types in the central nervous system, based on nuclear and cytoplasmic features, amongst other unique characteristics. From the basic distinction between neurons and their supporting cells, the glia, to differences in their subcellular compartments, organelles and their interactions, ultrastructural analyses can provide unique insights into the changes in brain function during aging and disease conditions, such as stroke, neurodegeneration, infection and trauma. Brain parenchyma is composed of a dense mixture of neuronal and glial cell bodies, together with their intertwined processes. Intracellular components that vary between cells, and can become altered with aging or disease, relate to the cytoplasmic and nucleoplasmic density, nuclear heterochromatin pattern, mitochondria, endoplasmic reticulum and Golgi complex, lysosomes, neurosecretory vesicles, and cytoskeletal elements (actin, intermediate filaments, and microtubules). Applying immunolabeling techniques to visualize membrane-bound or intracellular proteins in neurons and glial cells gives an even better appreciation of the subtle differences unique to these cells across contexts of health and disease. Together, our observations reveal how simple ultrastructural features can be used to identify specific changes in cell types, their health status, and functional relationships in the brain.

Presence of antibody in virus-infected brain cells of SSPE ferrets

1983 ◽  
Vol 41 ◽  
pp. 804-805
Author(s):  
Hannah R. Brown ◽  
Tammy L. Donato ◽  
Halldor Thormar
Keyword(s):  
Measles Virus ◽  
Plasma Cells ◽  
Subacute Sclerosing Panencephalitis ◽  
Protein A ◽  
Neutralizing Antibody ◽  
Brain Cells ◽  
Antibody Titers ◽  
A Cell ◽  
The Central Nervous System ◽  
The Brain

Measles virus specific immunoglobulin G (IgG) has been found in the brains of patients with subacute sclerosing panencephalitis (SSPE), a slowly progressing disease of the central nervous system (CNS) in children. IgG/albumin ratios indicate that the antibodies are synthesized within the CNS. Using the ferret as an animal model to study the disease, we have been attempting to localize the Ig's in the brains of animals inoculated with a cell associated strain of SSPE. In an earlier report, preliminary results using Protein A conjugated to horseradish peroxidase (PrAPx) (Dynatech Diagnostics Inc., South Windham, ME.) to detect antibodies revealed the presence of immunoglobulin mainly in antibody-producing plasma cells in inflammatory lesions and not in infected brain cells.In the present experiment we studied the brain of an SSPE ferret with neutralizing antibody titers of 1:1024 in serum and 1:512 in CSF at time of sacrifice 7 months after i.c. inoculation with SSPE measles virus-infected cells. The animal was perfused with saline and portions of the brain and spinal cord were immersed in periodate-lysine-paraformaldehyde (P-L-P) fixative. The ferret was not perfused with fixative because parts of the brain were used for virus isolation.

Glucuronyl 3-sulfate occurs exclusively on distal unmyelinated terminals of selected sensory neurons in the peripheral nervous system

1995 ◽  
Vol 53 ◽  
pp. 958-959
Author(s):  
S.S. Spicer ◽  
B.A. Schulte
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Cerebral Cortex ◽  
Peripheral Nervous System ◽  
Sensory Neurons ◽  
Sensory Nerves ◽  
Tissue Antigens ◽  
The Central Nervous System ◽  
The Brain ◽  
Leu 7

Generation of monoclonal antibodies (MAbs) against tissue antigens has yielded several (VC1.1, HNK- 1, L2, 4F4 and anti-leu 7) which recognize the unique sugar epitope, glucuronyl 3-sulfate (Glc A3- SO4). In the central nervous system, these MAbs have demonstrated Glc A3-SO4 at the surface of neurons in the cerebral cortex, the cerebellum, the retina and other widespread regions of the brain.Here we describe the distribution of Glc A3-SO4 in the peripheral nervous system as determined by immunostaining with a MAb (VC 1.1) developed against antigen in the cat visual cortex. Outside the central nervous system, immunoreactivity was observed only in peripheral terminals of selected sensory nerves conducting transduction signals for touch, hearing, balance and taste. On the glassy membrane of the sinus hair in murine nasal skin, just deep to the ringwurt, VC 1.1 delineated an intensely stained, plaque-like area (Fig. 1). This previously unrecognized structure of the nasal vibrissae presumably serves as a tactile end organ and to our knowledge is not demonstrable by means other than its selective immunopositivity with VC1.1 and its appearance as a densely fibrillar area in H&E stained sections.

Ultrastructural morphology of neurosecretory neurons in the barnacle Balanus amphitrite

1990 ◽  
Vol 48 (3) ◽  
pp. 434-435
Author(s):  
Grazia Tagliafierro ◽  
Cristiana Crosa ◽  
Marco Canepa ◽  
Tiziano Zanin
Keyword(s):  
Nervous System ◽  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Balanus Amphitrite ◽  
Neurosecretory Neurons ◽  
The Central Nervous System ◽  
Ultrathin Sections ◽  
Dense Core Granules ◽  
The Brain ◽  
Ocellar Nerve

Barnacles are very specialized Crustacea, with strongly reduced head and abdomen. Their nervous system is rather simple: the brain or supra-oesophageal ganglion (SG) is a small bilobed structure and the toracic ganglia are fused into a single ventral mass, the suboesophageal ganglion (VG). Neurosecretion was shown in barnacle nervous system by histochemical methods and numerous putative hormonal substances were extracted and tested. Recently six different types of dense-core granules were visualized in the median ocellar nerve of Balanus hameri and serotonin and FMRF-amide like substances were immunocytochemically detected in the nervous system of Balanus amphitrite. The aim of the present work is to localize and characterize at ultrastructural level, neurosecretory neuron cell bodies in the VG of Balanus amphitrite.Specimens of Balanus amphitrite were collected in the port of Genova. The central nervous system were Karnovsky fixed, osmium postfixed, ethanol dehydrated and Durcupan ACM embedded. Ultrathin sections were stained with uranyl acetate and lead citrate. Ultrastructural observations were made on a Philips M 202 and Zeiss 109 T electron microscopy.

Three-dimensional structure of dendritic spines, neuronal specializations that impart both stability and flexibility to synaptic function

1993 ◽  
Vol 51 ◽  
pp. 92-93
Author(s):  
Kristen M. Harris
Keyword(s):  
Dendritic Spines ◽  
Three Dimensional ◽  
Synaptic Function ◽  
Dimensional Structure ◽  
Excitatory Synapses ◽  
Concept Of Function ◽  
Section Electron ◽  
High Quality Information ◽  
The Central Nervous System ◽  
Mathematical Analyses

Dendritic spines are the tiny protrusions that stud the surface of many neurons and they are the location of over 90% of all excitatory synapses that occur in the central nervous system. Their small size and variable shapes has in large part made detailed study of their structure refractory to conventional light microscopy and single section electron microscopy (EM). Yet their widespread occurrence and likely involvement in learning and memory has motivated extensive efforts to obtain quantitative descriptions of spines in both steady state and dynamic conditions. Since the seminal mathematical analyses of D’Arcy Thompson, the power of establishing quantitatively key parameters of structure has become recognized as a foundation of successful biological inquiry. For dendritic spines highly precise determinations of structure and its variation are proving themselves as the kingpin for establishing a valid concept of function. The recent conjunction of high quality information about the structure, function, and theoretical implications of dendritic spines has produced a flurry of new considerations of their role in synaptic transmission.

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