The control of cell number in the lumbar spinal ganglia during the development of Xenopus laevis tadpoles

Development ◽  
1967 ◽  
Vol 17 (3) ◽  
pp. 453-471
Author(s):  
M. C. Prestige
Keyword(s):  
Dorsal Root ◽  
Early Stage ◽  
Subsequent Development ◽  
Cell Number ◽  
Limb Bud ◽  
Spinal Ganglia ◽  
Partial Removal ◽  
Motor Neurones ◽  
The Central Nervous System ◽  
Lumbar Spinal

It is the purpose of this paper to describe the development of the lumbar dorsal root ganglia after amputation of the leg. This operation can be performed at a very early stage before any connexions between the limb and the central nervous system are established. Alternatively, it can be performed at a number of later stages after the limb has been innervated. The extent of interaction can then be investigated for each stage by observing the subsequent development of the ganglia and comparing it with that of normal animals. Amputation of the limb-bud or the growing leg results in partial removal of the peripheral field for both sensory and motor neurones; the operation thus provides a means of investigating the mechanisms that control the processes of proliferation, maintenance, and degeneration of nerve cells. Detwiler and his colleagues (Detwiler, 1933) have shown that in Amblystoma loss of cells from the ganglia (hypoplasia) follows amputation, and that increase in number (hyperplasia) follows grafting of a supernumerary limb.

Rôle du nerf et du territoire cutané dans le développement des corpuscules de Herbst et de Grandry

Development ◽  
1972 ◽  
Vol 27 (2) ◽  
pp. 277-300
Author(s):  
Par Raymond Saxod
Keyword(s):  
Nerve Ending ◽  
Structural Integrity ◽  
Early Stage ◽  
Sensory Nerve ◽  
Chorioallantoic Membrane ◽  
Subsequent Development ◽  
Limb Bud ◽  
Spinal Ganglia ◽  
Schematic Model ◽  
Cutaneous Tissue

Role of nerve and cutaneous tissue in the development of Herbst's and Grandry's corpuscles Frontal buds or pieces of the bill of duck and chick embryos have been explanted on the chorioallantoic membrane, transplanted as homo- or xeno-plastic grafts to the flank, the frontal bud and the limb bud of early host embryos, or associated as coelomic grafts with various isolated nerve sources. Results show that: 1. The onset of the histogenesis of Herbst's and Grandry's cutaneous sensory corpuscles is entirely dependent on the presence of a nerve ending, irrespective of the stage at which the graft is obtained. The nerve ending is also required for the maintenance of the structural integrity of the previously differentiated corpuscles and for their subsequent development. 2. Only somato-sensory nerve endings are able to ensure the development of the corpuscles; central connexions are not required. Sympathetic or somato-motor fibres are not able to sustain the development of the corpuscles. 3. The corpuscle type, as well as corpuscle distribution, is in conformity with the origin of the integument in which it develops and is determined by the specificity and regional quality of the innervated dermal mesenchyme. The determination of the cutaneous territory occurs at a very early stage (prior to the 3rd day of incubation in the frontal bud of the duck). 4. Heterotopic or xenoplastic innervation of the graft between duck and chick does not alter the cutaneous specificity of the differentiation. However, corpuscles did not differentiate when duck frontal buds were innervated by mouse spinal ganglia. These results are discussed in connexion with what is known about peripheric sense organs in vertebrates. A schematic model is proposed for the mechanism of the morphogenesis of the corpuscles.

Effects of cyclophosphamide treatment before implantation on the development of rat embryos after implantation

Development ◽  
1977 ◽  
Vol 41 (1) ◽  
pp. 65-78
Author(s):  
Horst Spielmann ◽  
Hans-Georg Eibs ◽  
Hans-Joachim Merker
Keyword(s):  
Early Stage ◽  
Subsequent Development ◽  
Cell Number ◽  
Pregnant Rats ◽  
Cyclophosphamide Treatment ◽  
Wet Weight ◽  
Dose Dependent Decrease ◽  
Decidual Reaction ◽  
Dose Dependent

After treatment of pregnant rats 24 h before implantation with a single injection of cyclophosphamide (20–80 mg/kg), a dose-dependent increase in resorption was observed at term but no malformed fetuses could be found. The lowest cyclophosphamide dose that caused 100 % resorption was 60 mg/kg. Somite number and wet weight indicated retardation of about 24 h during organogenesis. Determination of the time of implantation revealed that the developmental retardation in treated embryos was not due to delayed implantation. At implantation, 24 h after cyclophosphamide treatment, a significant and dose-dependent decrease of the cell number of blastocysts was found. Embryo transplantation experiments showed that early cyclophosphamide treatment interfered with the subsequent development of both the embryo and the mother. The decidual reaction seemed to be more affected by the treatment than the embryos. Most teratologists hold that mouse embryos after treatment in the preimplantation period either die before implantation or survive to term without being malformed. The present study, however, proves that the reaction of drugs at this early stage of pregnancy is more complex than is generally assumed.

Memoirs: Variations in the Form of the Golgi Bodies during the Development of Neurones

1925 ◽  
Vol s2-69 (275) ◽  
pp. 509-517
Author(s):  
A. SUBBA RAU ◽  
R. J. LUDFORD
Keyword(s):  
Spinal Cord ◽  
Golgi Apparatus ◽  
Ganglion Cells ◽  
Early Stage ◽  
Golgi Body ◽  
Spinal Ganglia ◽  
Golgi Bodies ◽  
Stage Of Development ◽  
The Central Nervous System ◽  
High Degree

1. In the spinal ganglia of the chick of four days the Golgi apparatus or body is in the form of a cluster of granules or rodlets, grouped around the centrosphere, at one side of the nucleus (fig. 1, Pl. 39). 2. In a seven-day chick the Golgi body has increased in size and has begun to spread farther around the nucleus (fig. 3, Pl. 39). 3. All ganglion cells examined, both those of the spinal cord and of ganglia, have the Golgi apparatus in this compacted form during their early stage. 4. At a certain period which varies in the different cells the apparatus spreads out in the cytoplasm (fig. 4, Pl. 39), so that in the adult ganglia the apparatus is more or less scattered throughout the cell (figs. 5, 6, and 7, Pl. 39). 5. It is uncertain to what extent variations in the form of the apparatus, whether reticulate or in the form of individual rodlets, are due to differences in the degree of impregnation with the silver. The plane of the section is also an important factor in determining the appearance presented by the apparatus. 6. The medullary cells of the suprarenal body, which are derived from the central nervous system, have the apparatus in the form of a coiled network or cluster of granules at one pole of the nucleus, similar to the cells of the spinal ganglia at the early stage of development. 7. It is suggested that the scattered form of the Golgi apparatus in adult ganglion cells is an expression of the high degree of metabolism existing in these cells.

The innervation of the hind limb of Eleutherodactylus martinicensis: further comparison of cell and fiber numbers during development

Development ◽  
1972 ◽  
Vol 27 (2) ◽  
pp. 389-412
Author(s):  
Arthur Hughes ◽  
Margaret Egar
Keyword(s):  
Sciatic Nerve ◽  
Hind Limb ◽  
Ventral Horn ◽  
Spinal Ganglia ◽  
Early Juvenile ◽  
Unmyelinated Fibers ◽  
Myelinated And Unmyelinated Fibers ◽  
The Central Nervous System ◽  
Spinal Roots ◽  
Lumbar Spinal

In montages of electron micrographs of the sciatic nerve of Eleutherodactylus martinicensis, the numbers of fibers of all classes have been counted, from the 8·5 day embryo, through the early juvenile to the adult. These counts have been compared with the total numbers of cells in the lumbar ventral horn plus those in the lumbar spinal ganglia 8, 9 and 10. In the embryo, both sets of counts rise to a peak on the 13th day, and fall early in the 14th day. In the embryo, the cell count is 600–1000 more than the fiber count, while in the 6-day juvenile onwards, the fiber count is the greater. These differences are held to arise from the play of two independent factors, namely production of axons in the embryo by only a minority of cells in ganglia and ventral horns, and secondly, the extent to which axons branch between spinal roots and sciatic nerve at all stages. In the embryo, numbers of cells and fibers maintain a parallel course up and down the 13-day peak, indicating that many cells which are lost by degeneration had already sent axons into the nerve. Myelinated fibers first appear in the limb nerves at 8·5 days, when limb motility is first seen. The course of formation of the earliest myelin in the sciatic nerve resembles that of fibers in the central nervous system. In spinal roots there are both myelinated and unmyelinated fibers, the proportion of the latter in ventral roots being the greater.

scholarly journals Development of the Cerebrospinal Fluid in Early Stage after Hemorrhage in the Central Nervous System

Life ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 300
Author(s):  
Petr Kelbich ◽  
Aleš Hejčl ◽  
Jan Krejsek ◽  
Tomáš Radovnický ◽  
Inka Matuchová ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Cerebrospinal Fluid ◽  
Nervous System ◽  
Early Stage ◽  
Rank Test ◽  
Signed Rank ◽  
Signed Rank Test ◽  
The Central Nervous System ◽  
Poor Outcomes ◽  
Molecular Patterns

Extravasation of blood in the central nervous system (CNS) represents a very strong damaged associated molecular patterns (DAMP) which is followed by rapid inflammation and can participate in worse outcome of patients. We analyzed cerebrospinal fluid (CSF) from 139 patients after the CNS hemorrhage. We compared 109 survivors (Glasgow Outcome Score (GOS) 5-3) and 30 patients with poor outcomes (GOS 2-1). Statistical evaluations were performed using the Wilcoxon signed-rank test and the Mann–Whitney U test. Almost the same numbers of erythrocytes in both subgroups appeared in days 0–3 (p = 0.927) and a significant increase in patients with GOS 2-1 in days 7–10 after the hemorrhage (p = 0.004) revealed persistence of extravascular blood in the CNS as an adverse factor. We assess 43.3% of patients with GOS 2-1 and only 27.5% of patients with GOS 5-3 with low values of the coefficient of energy balance (KEB < 15.0) in days 0–3 after the hemorrhage as a trend to immediate intensive inflammation in the CNS of patients with poor outcomes. We consider significantly higher concentration of total protein of patients with GOS 2-1 in days 0–3 after hemorrhage (p = 0.008) as the evidence of immediate simultaneously manifested intensive inflammation, swelling of the brain and elevation of intracranial pressure.

scholarly journals Astrocytic transporters in Alzheimer's disease

2017 ◽  
Vol 474 (3) ◽  
pp. 333-355 ◽  
Author(s):  
Chris Ugbode ◽  
Yuhan Hu ◽  
Benjamin Whalley ◽  
Chris Peers ◽  
Marcus Rattray ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Early Stage ◽  
Neurological Diseases ◽  
Current Evidence ◽  
Specific Targeting ◽  
Disease Modifying Therapies ◽  
The Central Nervous System ◽  
Disease Modifying ◽  
And Function

Astrocytes play a fundamental role in maintaining the health and function of the central nervous system. Increasing evidence indicates that astrocytes undergo both cellular and molecular changes at an early stage in neurological diseases, including Alzheimer's disease (AD). These changes may reflect a change from a neuroprotective to a neurotoxic phenotype. Given the lack of current disease-modifying therapies for AD, astrocytes have become an interesting and viable target for therapeutic intervention. The astrocyte transport system covers a diverse array of proteins involved in metabolic support, neurotransmission and synaptic architecture. Therefore, specific targeting of individual transporter families has the potential to suppress neurodegeneration, a characteristic hallmark of AD. A small number of the 400 transporter superfamilies are expressed in astrocytes, with evidence highlighting a fraction of these are implicated in AD. Here, we review the current evidence for six astrocytic transporter subfamilies involved in AD, as reported in both animal and human studies. This review confirms that astrocytes are indeed a viable target, highlights the complexities of studying astrocytes and provides future directives to exploit the potential of astrocytes in tackling AD.

Does Motor Learning Occur in the Spinal Cord?

1997 ◽  
Vol 3 (5) ◽  
pp. 287-294 ◽  
Author(s):  
V. Reggie Edgerton ◽  
Roland R. Roy ◽  
Ray De Leon Niranjala Tillakaratne ◽  
John A. Hodgson
Keyword(s):  
Spinal Cord ◽  
Motor Task ◽  
Lumbar Spinal Cord ◽  
Lumbosacral Spinal Cord ◽  
Patterns Of Use ◽  
The Neural Network ◽  
The Central Nervous System ◽  
Network Plasticity ◽  
Lumbar Spinal ◽  
The Brain

It is becoming clear that the plasticity of the sensory-motor networks of the adult mammalian lumbosacral spinal cord is much greater than and is more dependent on the specific patterns of use than has been previously assumed. Using a wide variety of experimental paradigms in which the lumbar spinal cord is isolated from the brain, it has been shown that the lumbosacral spinal cord can learn to execute stepping or standing more successfully if that specific task is practiced. It also appears that the sensory input associated with the motor task and/or the manner in which it is interpreted by the spinal cord are important components of the neural network plasticity. Early evidence suggests that several neurotransmitter systems in the spinal cord, to include glycinergic and GABAergic systems, adapt to repetitive use. These studies extend a growing body of evidence suggesting that memory and learning are widely distributed phenomena within the central nervous system. NEUROSCIENTIST 3:287–294, 1997

Sensory and Motor Neurones Responsible for the Local Bending Response in Leeches

1982 ◽  
Vol 96 (1) ◽  
pp. 161-180 ◽  
Author(s):  
WILLIAM B. KRISTAN
Keyword(s):  
Body Wall ◽  
Longitudinal Muscle ◽  
Motor Neurone ◽  
Intracellular Recordings ◽  
Firing Rates ◽  
Macrobdella Decora ◽  
Motor Neurones ◽  
The Central Nervous System ◽  
P Cells ◽  
Bending Response

1. Intracellular recordings were made from identified mechanosensory neurones (T and P cells) and longitudinal muscle motor neurones of leeches Hirudo medicinalis and Macrobdella decora while the skin was electrically stimulated to produce local bending responses. 2. The stimulus intensity required to produce local bending was found to activate the mechanosensory neurones at physiological firing rates. For a given stimulation frequency, intracellular activation of the mechanosensory neurones produced the same local bending response as did skin stimulation. Hyperpolarization sufficient to block the propagation of the afferent impulses into the central nervous system eliminated the local bending response to skin stimulation. 3. Stimulating identified longitudinal muscle motor neurones at frequencies observed during the local bending response produced body wall movements similar to those seen in local bending. Hyperpolarization of the motor neurones to block impulse initiation abolished local bending. 4. Mechanosensory neurone to longitudinal muscle motor neurone connexions were demonstrated to be effective and reliable, but polysynaptic for all but the previously documented monosynaptic connexions from mechanosensory neurones onto the L motor neurone (Nicholls & Purves, 1970). 5. It is concluded that the previously identified mechanosensory and motor neurones are exclusively responsible for the local bending response.

A quantitative study of the growth and development of the ventral root in normal and experimental conditions

Development ◽  
1974 ◽  
Vol 32 (3) ◽  
pp. 819-833
Author(s):  
M. C. Prestige ◽  
Margaret A. Wilson
Keyword(s):  
Normal Development ◽  
Cell Number ◽  
Ventral Horn ◽  
Ventral Root ◽  
Limb Bud ◽  
Experimental Conditions ◽  
Collateral Sprouting ◽  
Cell Counts ◽  
Ventral Roots ◽  
Fibre Loss

1. The development of the ventral root (VR) in Xenopus has been studied by electron microscopy. Total fibre counts, and counts of classes of fibres were made from large photomontages of the whole of VR 9 at × 15000. 2. The total number of fibres in the root shows the same pattern of initial rise, peak, and subsequent decline that previous ventral horn (VH) cell counts had shown, The two curves overlay each other initially, but after the decline, there were apparently more cells than fibres. 3. Promyelin and myelin formation was seen at the time of the decline. There was no evidence that dying axons had started to myelinate. 4. In some animals the limb-bud was removed at the time of its first penetration by nerve fibres. The ventral roots developed normally for a week, but thereafter fibre loss was accentuated, advanced and more profound, so that after another week, no fibres were left. In these roots, no promyelin or myelin was formed. 5. In other animals, it was shown that there is no evidence for collateral sprouting in the ventral roots during normal development. 6. It is argued that the axons which die in normal development have already reached the limb-bud. 7. The correspondence between axon and cell number is discussed.

scholarly journals Treatment Efficiency in Gaucher Patients Can Reliably Be Monitored by Quantification of Lyso-Gb1 Concentrations in Dried Blood Spots

2020 ◽  
Vol 21 (13) ◽  
pp. 4577 ◽  
Author(s):  
Claudia Cozma ◽  
Paskal Cullufi ◽  
Guido Kramp ◽  
Marina Hovakimyan ◽  
Virtut Velmishi ◽  
...  
Keyword(s):  
Early Stage ◽  
Subsequent Development ◽  
High Sensitivity ◽  
Dried Blood Spots ◽  
Lysosomal Storage ◽  
Treatment Efficiency ◽  
Blood Spots ◽  
Enzyme Replacement ◽  
Treatment Conditions ◽  
Clinical Consequences

Gaucher disease (GD) is a lysosomal storage disorder that responds well to enzyme replacement therapy (ERT). Certain laboratory parameters, including blood concentration of glucosylsphingosine (Lyso-Gb1), the lyso-derivate of the common glycolipid glucocerebroside, correlate with clinical improvement and are therefore considered candidate-monitoring biomarkers. Whether they can indicate a reduction or loss of treatment efficiency, however, has not been systematically addressed for obvious reasons. We established and validated measurement of Lyso-Gb1 from dried blood spots (DBSs) by mass spectrometry. We then characterized the assay’s longitudinal performance in 19 stably ERT-treated GD patients by dense monitoring over a 3-year period. The observed level of fluctuation was accounted for in the subsequent development of a unifying data normalization concept. The resulting approach was eventually applied to data from Lyso-Gb1 measurements after an involuntary treatment break for all 19 patients. It enabled separation of the “under treatment” versus “not under treatment” conditions with high sensitivity and specificity. We conclude that Lyso-Gb1 determination from DBSs indicates treatment issues already at an early stage before clinical consequences arise. In addition to its previously shown diagnostic utility, Lyso-Gb1 thereby qualifies as a monitoring biomarker in GD patients.

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