Activation of Pax6 depends on somitogenesis in the chick embryo cervical spinal cord

Development ◽  
1999 ◽  
Vol 126 (3) ◽  
pp. 587-596 ◽  
Author(s):  
F. Pituello ◽  
F. Medevielle ◽  
F. Foulquier ◽  
A.M. Duprat
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Homeobox Gene ◽  
Neural Plate ◽  
Paraxial Mesoderm ◽  
Presomitic Mesoderm ◽  
Pax6 Expression ◽  
The Central Nervous System ◽  
Initial Activation ◽  
Host Embryo

Pax6 is a paired-type homeobox gene expressed in discrete regions of the central nervous system. In the spinal cord of 7- to 10-somite-stage chicken embryos, Pax6 is not detected within the caudal neural plate, but is progressively upregulated in the neuroepithelium neighbouring each newly formed somite. In the present study, we accumulate data suggesting that this initial activation of Pax6 is controlled via the paraxial mesoderm in correlation with somitogenesis. First, we observed that high levels of Pax6 expression occur independently of the presence of SHH-expressing cells when neural plates are maintained in culture in the presence of paraxial mesoderm. Second, grafting a somite caudally under a neural plate that has not yet expressed the gene induces a premature activation of Pax6. Furthermore, after the graft of a somite, a period of incubation corresponding to the individualization of a new somite in the host embryo produces an appreciable activation of Pax6. Conversely, Pax6 expression is delayed under conditions where somitogenesis is retarded, i.e., when the rostral part of the presomitic mesoderm is replaced by the same tissue isolated more caudally. Finally, Pax6 transcripts disappear from the neural tube when a somite is replaced by presomitic mesoderm, suggesting that the somite is also involved in the maintenance of Pax6 expression in the developing spinal cord. All together these observations lead to the proposal that Pax6 activation is triggered by the paraxial mesoderm in phase with somitogenesis in the cervical spinal cord.

FGF signalling controls the timing of Pax6 activation in the neural tube

Development ◽  
2000 ◽  
Vol 127 (22) ◽  
pp. 4837-4843 ◽  
Author(s):  
N. Bertrand ◽  
F. Medevielle ◽  
F. Pituello
Keyword(s):  
Spinal Cord ◽  
Neural Tube ◽  
Inhibitory Activity ◽  
Neural Plate ◽  
Presomitic Mesoderm ◽  
Pax6 Expression ◽  
Epithelial Development ◽  
Repressive Effect ◽  
Caudal Regression ◽  
Fgf Signalling

We have recently demonstrated that Pax6 activation occurs in phase with somitogenesis in the spinal cord. Here we show that the presomitic mesoderm exerts an inhibitory activity on Pax6 expression. This repressive effect is mediated by the FGF signalling pathway. The presomitic mesoderm displays a decreasing caudorostral gradient of FGF8, and grafting FGF8-soaked beads at the level of the neural tube abolishes Pax6 activation. Conversely, when FGF signalling is disrupted, Pax6 is prematurely activated in the neural plate. We propose that the progression of Pax6 activation in the neural tube is controlled by the caudal regression of the anterior limit of FGF activity. Hence, as part of its posteriorising activity, FGF8 downregulation acts as a switch from early (posterior) to a later (anterior) state of neural epithelial development.

Neurodevelopment

2020 ◽  
pp. 91-100
Author(s):  
Karl Zilles ◽  
Nicola Palomero-Gallagher
Keyword(s):  
Spinal Cord ◽  
Nervous System ◽  
Neural Tube ◽  
Neural Plate ◽  
Adult Brain ◽  
The Central Nervous System ◽  
Specialized Region ◽  
The Brain ◽  
Rostral Part ◽  
Human Nervous System

The pre- and post-natal development of the human nervous system is briefly described, with special emphasis on the brain, particularly the cerebral and cerebellar cortices. The central nervous system originates from a specialized region of the ectoderm—the neural plate—which develops into the neural tube. The rostral part of the neural tube forms the adult brain, whereas the caudal part (behind the fifth somite) differentiates into the spinal cord. The embryonic brain has three vesicular enlargements: the forebrain, the midbrain, and the hindbrain. The histogenesis of the spinal cord, hindbrain, cerebellum, and cerebral cortex, including myelination, is discussed. The chapter closes with a description of the development of the hemispheric shape and the formation of gyri.

Correlation of MRI with the Neuropathologic Changes in Two Cats with Bromethalin Intoxication

2019 ◽  
Vol 55 (3) ◽  
Author(s):  
Marc Kent ◽  
Eric N. Glass ◽  
Lindsay Boozer ◽  
Rachel B. Song ◽  
Elyshia J. Hankin ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Differential Diagnosis ◽  
White Matter ◽  
Cervical Spinal Cord ◽  
Spongy Degeneration ◽  
Intramyelinic Edema ◽  
Apparent Diffusion ◽  
The Central Nervous System ◽  
Uncoupling Of Oxidative Phosphorylation ◽  
T2 Hyperintensity

ABSTRACT Two cats were presented with multifocal neurological signs. One cat’s signs progressed over 2 wk; the other cat progressed over 5 days. Examinations were consistent with a process involving the prosencephalon, vestibular system, and general proprioceptive/upper motor neuron systems. MRI of the brain and cervical spinal cord reveal widespread T2 hyperintensity of the white matter. Affected areas included the cerebrum, cerebral peduncles, corticospinal tracts of the pons and medulla, and the cerebellum. T2 hyperintensity was present in all funiculi of the spinal cord. Diffusion-weighted imaging (DWI) and apparent diffusion coefficient (ADC) maps were consistent with cytotoxic or intramyelinic edema. Differential diagnosis included toxic or metabolic/degenerative leukoencephalopathies. Necropsies revealed widespread spongy degeneration of the central nervous system white matter. Toxicologic assays of liver specimens revealed desmethylbromethalin, a metabolite of bromethalin. Bromethalin is a rodenticide that causes uncoupling of oxidative phosphorylation. Antemortem diagnosis is challenging. DWI and ADC maps were instrumental in narrowing the differential diagnosis and raised the index of suspicion for bromethalin. Bromethalin intoxication should be considered in all animals with a progressive course of multifocal neurologic deficits. MRI, specifically, DWI and ADC maps, may serve as a biomarker of cytotoxic or intramyelinic edema associated with spongiform leukoencephalomyelopathy.

Peripheral and brain tissue catecholamine content in intact and anti-NGF-treated fetal sheep

1987 ◽  
Vol 252 (1) ◽  
pp. R7-R12 ◽  
Author(s):  
J. A. Schuijers ◽  
D. W. Walker ◽  
C. A. Browne ◽  
G. D. Thorburn
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Gestational Age ◽  
Adrenal Glands ◽  
Matched Control ◽  
Cervical Spinal Cord ◽  
Fetal Sheep ◽  
Catecholamine Content ◽  
The Central Nervous System

Fetal lambs were treated with a single dose of anti-mouse nerve growth factor (anti-NGF) at 80 days gestational age. The catecholamine content of tissues was determined at 135 days gestational age. There was a reduction of either norepinephrine, epinephrine, or both, in the thymus, thyroid, atrium (but not ventricle), lung, liver, kidney, and jejunum when compared with age-matched control fetuses. The spleen, ileum, colon, and the adrenal glands were not affected by anti-NGF. In treated fetuses there was a reduction in catecholamine content of the thalamus, hypothalamus, hippocampus, medulla, cerebellum, and cervical spinal cord. These results show that some tissues are sensitive to, and some are refractory to, the action of anti-NGF at 80 days gestation. Also the results suggest that NGF may play a role in the development of catecholamine-containing neurons within the central nervous system.

scholarly journals Multiple nocardial abscesses of the brainstem and spinal cord diagnosed after an open biopsy through a cervical partial central corpectomy: case report

2015 ◽  
Vol 23 (3) ◽  
pp. 290-293 ◽  
Author(s):  
Ian Peeters ◽  
Jan W. Casselman ◽  
Stefaan J. Vandecasteele ◽  
Alexander Janssen ◽  
Bart Regaert ◽  
...  
Keyword(s):  
Spinal Cord ◽  
Cervical Spinal Cord ◽  
Emission Tomography ◽  
Open Biopsy ◽  
Difficult Diagnosis ◽  
Positron Emission ◽  
The Central Nervous System ◽  
Walking Difficulty ◽  
Brain And Spinal Cord ◽  
The Brain

Nocardiosis of the central nervous system is a challenging and difficult diagnosis for the clinician. The combination of infections of the brain and spinal cord is even more rare. The authors report on a patient with multiple lesions in the brainstem and cervical spinal cord. This 81-year-old immunocompetent woman presented with symptoms of progressive walking difficulty and ataxia. The results of an extensive workup with laboratory investigation, MRI, lumbar puncture, positron emission tomography (PET), and bone marrow biopsy remained inconclusive. Only after an open biopsy of a cervical lesion by an anterior approach through a partial central corpectomy of the cervical spine, was the diagnosis of nocardiosis made, allowing for specific antibiotic treatment.

scholarly journals Case Report: Primary Diffuse Leptomeningeal Oligodendrogliomatosis in a Young Adult Cat

2021 ◽  
Vol 8 ◽  
Author(s):  
Elisa Chludzinski ◽  
Christina Puff ◽  
Jürgen Weber ◽  
Marion Hewicker-Trautwein
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Cervical Spinal Cord ◽  
Round Cell ◽  
Ki 67 ◽  
Progressive Ataxia ◽  
Proliferation Activity ◽  
The Central Nervous System ◽  
Adult Cat

A 2-year-old cat was presented with progressive ataxia. Despite treatment the animal died. Pathomorphological examination revealed a widespread leptomeningeal mass at all levels of the central nervous system accentuated on the cervical spinal cord and the medulla oblongata without presence of a primary intraaxial tumor. The neoplasm was mainly composed of round, uninucleate cells with hyperchromatic nuclei, which were immunopositive for OLIG2, doublecortin, MAP2, synaptophysin, and vimentin, indicating components of both oligodendroglial and neuronal differentiation. Ki-67 immunohistochemistry indicated a high proliferation activity of the neoplasm. Few GFAP positive and Iba-1 positive cells were interpreted as reactive astrocytes and macrophages or microglia, respectively. The tumor was immunonegative for CD3, CD20, PAX5, MUM1, pan-cytokeratin, S100, NSE, p75NTR, NeuN and periaxin. These findings led to the diagnosis of primary diffuse leptomeningeal oligodendrogliomatosis. This is the first reported case of this entity in a young cat, which should be considered as a differential diagnosis for diffuse subarachnoidal round cell infiltrates.

Radiation-induced Cerebellar Glioblastoma Multiforme Subsequent to Treatment of an Astrocytoma of the Cervical Spinal Cord

Neurosurgery ◽  
1991 ◽  
Vol 29 (4) ◽  
pp. 606-608 ◽  
Author(s):  
Zvi H. Rappaport ◽  
David Loven ◽  
Uriel Ben-Aharon
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Glioblastoma Multiforme ◽  
Cervical Spinal Cord ◽  
Induced Tumors ◽  
Cerebellar Glioblastoma ◽  
Radiation Induced ◽  
The Central Nervous System ◽  
Radiation Induced Tumors

Abstract A cerebellar glioblastoma multiforme was diagnosed in a 22-year-old woman. This originated in the zone adjacent to a field irradiated 14 years earlier after the removal of a noncontiguous astrocytoma of the spinal cord. The accepted criteria for radiation-induced tumors of the central nervous system are discussed.

Histological features of neural induction in Xenopus laevis

Development ◽  
1971 ◽  
Vol 26 (3) ◽  
pp. 543-570
Author(s):  
D. Tarin
Keyword(s):  
Xenopus Laevis ◽  
Neural Induction ◽  
Neural Plate ◽  
Paraxial Mesoderm ◽  
Intestinal Tube ◽  
Spinal Cord Regions ◽  
The Central Nervous System ◽  
Dorsal Ectoderm ◽  
Two Stages ◽  
The Brain

It was first established by grafting experiments that neural induction occurs in Xenopus laevis and that it is the mesoderm in the dorsal lip of the blastopore which normally exercises this function. The subsequent histological work provided the following information: At stage 10½ mesodermal invagination was already well under way, in advance of the formation of the archenteric cavity. This confirms the earlier observations of Nieuwkoop & Florschutz(1950). The first evidence of neural induction, thickening of the mid-dorsal ectoderm combined with the development of an inner tier of columnar cells, occurred at stage 11½. By stage 12 there was generalized thickening of the dorsal ectoderm and between stage 12½ and 13 the brain and spinal cord regions of the neural plate became distinguishable. The dorsal mesoderm segregated into notochord rudiment and two lateral masses at stage 13 and the latter further subdivided into paraxial mesoderm and lateral plates by stage 14. The margins of the neural plate were clearly distinguished from presumptive epidermis by stage 15 and the median neural groove was also well marked. In the next two stages the folding of the neural plate in the line of this groove proceeded rapidly. The dorsoventral enlargement of the somites and the relative shrinkage of the notochord were considered to contribute to the mechanism of neurulation. Regionalization of the brain into prosencephalon, mesencephalon and rhombencephalon was in progress at stages 18 and 19. These results indicate that induction consists of an initial activation of dorsal ectoderm (generalized thickening) followed by gradual transformation of the neural plate to form the different parts of the central nervous system (regionalization). Intercellular metachromatic material was noted in various parts of the embryo. This was most plentiful between stage 10½ and stage 13 and thereafter gradually decreased. It was the only feature which persisted long enough to represent a possible inductive agent. At all stages the archenteron was lined with a continuous layer of endoderm. This indicates that the mode of formation of the gastro-intestinal tube in Xenopus is different to that in urodeles. It further implies that the mesoderm is not present on the blastular surface prior to gastrulation but lies in deeper layers.

scholarly journals Acute Respiratory Failure due to Neuromyelitis Optica Treated Successfully with Plasmapheresis

2016 ◽  
Vol 2016 ◽  
pp. 1-3
Author(s):  
Massa Zantah ◽  
Timothy B. Coyle ◽  
Debapriya Datta
Keyword(s):  
Spinal Cord ◽  
Central Nervous System ◽  
Nervous System ◽  
Respiratory Failure ◽  
Acute Respiratory Failure ◽  
Neuromyelitis Optica ◽  
Cervical Spinal Cord ◽  
High Dose ◽  
Pulse Dose ◽  
The Central Nervous System

Neuromyelitis Optica (NMO) is a demyelinating autoimmune disease involving the central nervous system. Acute respiratory failure from cervical myelitis due to NMO is known to occur but is uncommon in monophasic disease and is treated with high dose steroids. We report a case of a patient with NMO who developed acute respiratory failure related to cervical spinal cord involvement, refractory to pulse dose steroid therapy, which resolved with plasmapheresis.

scholarly journals Radiation-Induced Cervical Spinal Cord Cavernoma Following Head and Neck Radiotherapy: Case Report

2020 ◽  
Vol 81 (03) ◽  
pp. e39-e41
Author(s):  
Hosam Al-Jehani ◽  
Ahmad Najjar ◽  
Abdulwahid Barnawi ◽  
Daniel Shedid
Keyword(s):  
Spinal Cord ◽  
Radiation Therapy ◽  
Head And Neck ◽  
Cervical Spinal Cord ◽  
Vascular Malformations ◽  
Triggering Factor ◽  
Radiation Induced ◽  
The Central Nervous System ◽  
Head And Neck Radiation ◽  
Head And Neck Radiotherapy

AbstractCavernous angiomas are congenital vascular malformations that affect the central nervous system. Reports implicated radiation therapy as a triggering factor for the formation of cavernomas but not in relation with head and neck radiation therapy. Radiation-induced cavernomas (RIC) should be considered in the differential diagnosis of focal neurological symptoms in any patient who has received previous cranial-spinal or head and neck radiotherapy.

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