scholarly journals BMP controls dorsoventral and neural patterning in indirect-developing hemichordates providing insight into a possible origin of chordates

2019 ◽  
Vol 116 (26) ◽  
pp. 12925-12932 ◽  
Author(s):  
Yi-Hsien Su ◽  
Yi-Chih Chen ◽  
Hsiu-Chi Ting ◽  
Tzu-Pei Fan ◽  
Ching-Yi Lin ◽  
...  
Keyword(s):  
Nervous System ◽  
Morphological Changes ◽  
Sister Group ◽  
Neural Plate ◽  
Bmp Signaling ◽  
Neural Patterning ◽  
Mechanistic Basis ◽  
Lateral Organization ◽  
Insight Into ◽  
Origin Of Chordates

A defining feature of chordates is the unique presence of a dorsal hollow neural tube that forms by internalization of the ectodermal neural plate specified via inhibition of BMP signaling during gastrulation. While BMP controls dorsoventral (DV) patterning across diverse bilaterians, the BMP-active side is ventral in chordates and dorsal in many other bilaterians. How this phylum-specific DV inversion occurs and whether it is coupled to the emergence of the dorsal neural plate are unknown. Here we explore these questions by investigating an indirect-developing enteropneust from the hemichordate phylum, which together with echinoderms form a sister group of the chordates. We found that in the hemichordate larva, BMP signaling is required for DV patterning and is sufficient to repress neurogenesis. We also found that transient overactivation of BMP signaling during gastrulation concomitantly blocked mouth formation and centralized the nervous system to the ventral ectoderm in both hemichordate and sea urchin larvae. Moreover, this mouthless, neurogenic ventral ectoderm displayed a medial-to-lateral organization similar to that of the chordate neural plate. Thus, indirect-developing deuterostomes use BMP signaling in DV and neural patterning, and an elevated BMP level during gastrulation drives pronounced morphological changes reminiscent of a DV inversion. These findings provide a mechanistic basis to support the hypothesis that an inverse chordate body plan emerged from an indirect-developing ancestor by tinkering with BMP signaling.

A morphogen gradient of Wnt/β-catenin signalling regulates anteroposterior neural patterning in Xenopus

Development ◽  
2001 ◽  
Vol 128 (21) ◽  
pp. 4189-4201 ◽  
Author(s):  
Clemens Kiecker ◽  
Christof Niehrs
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neural Plate ◽  
Morphogen Gradient ◽  
Neural Cells ◽  
Neural Patterning ◽  
Molecular Identity ◽  
Spemann's Organizer ◽  
Necessary And Sufficient ◽  
Dose Dependent

Anteroposterior (AP) patterning of the vertebrate neural plate is initiated during gastrulation and is regulated by Spemann’s organizer and its derivatives. The prevailing model for AP patterning predicts a caudally increasing gradient of a ‘transformer’ which posteriorizes anteriorly specified neural cells. However, the molecular identity of the transforming gradient has remained elusive. We show that in Xenopus embryos (1) dose-dependent Wnt signalling is both necessary and sufficient for AP patterning of the neuraxis, (2) Wnt/β-catenin signalling occurs in a direct and long-range fashion within the ectoderm, and (3) that there is an endogenous AP gradient of Wnt/β-catenin signalling in the presumptive neural plate of the Xenopus gastrula. Our results indicate that an activity gradient of Wnt/β-catenin signalling acts as transforming morphogen to pattern the Xenopus central nervous system.

scholarly journals Atypical cutaneous and musculoskeletal manifestation of SARS-CoV-2: ‘COVID-19 toes’ and spasticity in a 48-year-old woman

2021 ◽  
Vol 14 (3) ◽  
pp. e241410
Author(s):  
Avery Kopacz ◽  
Cameron Ludwig ◽  
Michelle Tarbox
Keyword(s):  
Nervous System ◽  
Adult Patient ◽  
Early Identification ◽  
Lower Limbs ◽  
Rare Occurrence ◽  
Cutaneous Manifestations ◽  
Crucial Component ◽  
History Of ◽  
Screening Questions ◽  
Insight Into

Establishing accurate symptomatology associated with novel diseases such as COVID-19 is a crucial component of early identification and screening. This case report identifies an adult patient with a history of clotting dysfunction presenting with rare cutaneous manifestations of COVID-19, known as ‘COVID-19 toes’', previously described predominantly in children. Additionally, this patient presented with possible COVID-associated muscle spasticity of the lower limbs, as well as a prolonged and atypical timeline of COVID-19 infection. The rare occurrence of ‘COVID-19 toes’' in this adult patient suggests that her medical history could have predisposed her to this symptom. This supports the coagulopathic hypothesis of this manifestation of COVID-19 and provides possible screening questions for patients with a similar history who might be exposed to the virus. Additionally, nervous system complaints associated with this disease are rare and understudied, so this novel symptom may also provide insight into this aspect of SARS-CoV-2.

The Dependence of the Cellular Transformation of the Competent Ectoderm on Temporal Relationships in the Induction Process

Development ◽  
1958 ◽  
Vol 6 (3) ◽  
pp. 479-485
Author(s):  
Sulo Toivonen
Keyword(s):  
Nervous System ◽  
Early Development ◽  
Cellular Transformation ◽  
Neural Plate ◽  
Amphibian Embryo ◽  
Temporal Relationships ◽  
Induction Process ◽  
New Hypothesis

In 1952, Nieuwkoop et al. suggested a new hypothesis concerning the induction phenomenon determining the early development of the amphibian embryo. This hypothesis was based on cleverly planned experiments in which folds of competent epidermis were transplanted on to different regions of the neural plate of the neurula. According to this hypothesis, the invaginating archenteron roof is supposed first to activate the overlying ectoderm, enabling it to develop autonomously to archencephalon and its derivatives. This same archenteron roof is later thought to exert a second effect, which they called transformation. This second action is considered responsible for modifying the differentiation tendencies of the activated archencephalon so as to result in structures typical of more caudal regions of the nervous system. This process is regarded as a quantitative one, so that with increasing strength of transformation, the differentiation tendencies would be progressively more caudal.

scholarly journals Dual Inhibition of Activin/Nodal/TGF-βand BMP Signaling Pathways by SB431542 and Dorsomorphin Induces Neuronal Differentiation of Human Adipose Derived Stem Cells

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Vedavathi Madhu ◽  
Abhijit S. Dighe ◽  
Quanjun Cui ◽  
D. Nicole Deal
Keyword(s):  
Stem Cells ◽  
Nervous System ◽  
Neuronal Differentiation ◽  
Adult Stem Cells ◽  
Embryonic Stem ◽  
Bmp Signaling ◽  
Specific Marker ◽  
Adipose Derived Stem Cells ◽  
Neuronal Marker ◽  
Dual Inhibition

Damage to the nervous system can cause devastating diseases or musculoskeletal dysfunctions and transplantation of progenitor stem cells can be an excellent treatment option in this regard. Preclinical studies demonstrate that untreated stem cells, unlike stem cells activated to differentiate into neuronal lineage, do not survive in the neuronal tissues. Conventional methods of inducing neuronal differentiation of stem cells are complex and expensive. We therefore sought to determine if a simple, one-step, and cost effective method, previously reported to induce neuronal differentiation of embryonic stem cells and induced-pluripotent stem cells, can be applied to adult stem cells. Indeed, dual inhibition of activin/nodal/TGF-βand BMP pathways using SB431542 and dorsomorphin, respectively, induced neuronal differentiation of human adipose derived stem cells (hADSCs) as evidenced by formation of neurite extensions, protein expression of neuron-specific gamma enolase, and mRNA expression of neuron-specific transcription factors Sox1 and Pax6 and matured neuronal marker NF200. This process correlated with enhanced phosphorylation of p38, Erk1/2, PI3K, and Akt1/3. Additionally,in vitrosubcutaneous implants of SB431542 and dorsomorphin treated hADSCs displayed significantly higher expression of active-axonal-growth-specific marker GAP43. Our data offers novel insights into cell-based therapies for the nervous system repair.

An atomic-level insight into the basic mechanism responsible for the enhancement of the catalytic oxidation of carbon monoxide on a Cu/CeO2 surface

2017 ◽  
Vol 19 (5) ◽  
pp. 3498-3505 ◽  
Author(s):  
Kenichi Koizumi ◽  
Katsuyuki Nobusada ◽  
Mauro Boero
Keyword(s):  
Carbon Monoxide ◽  
Reaction Mechanism ◽  
Catalytic Oxidation ◽  
Morphological Changes ◽  
Basic Mechanism ◽  
Atomic Level ◽  
Insight Into ◽  
Oxidation Of Carbon Monoxide

Reaction mechanism of CO molecules onto a Cu/CeO2 surface and morphological changes.

scholarly journals Neuropeptides and Behaviors: How Small Peptides Regulate Nervous System Function and Behavioral Outputs

2021 ◽  
Vol 14 ◽  
Author(s):  
Umer Saleem Bhat ◽  
Navneet Shahi ◽  
Siju Surendran ◽  
Kavita Babu
Keyword(s):  
Nervous System ◽  
Behavioral Plasticity ◽  
Environmental Changes ◽  
Sensory Information ◽  
Synaptic Activity ◽  
Small Peptides ◽  
C Elegans ◽  
Wide Range ◽  
Nervous System Function ◽  
Insight Into

One of the reasons that most multicellular animals survive and thrive is because of the adaptable and plastic nature of their nervous systems. For an organism to survive, it is essential for the animal to respond and adapt to environmental changes. This is achieved by sensing external cues and translating them into behaviors through changes in synaptic activity. The nervous system plays a crucial role in constantly evaluating environmental cues and allowing for behavioral plasticity in the organism. Multiple neurotransmitters and neuropeptides have been implicated as key players for integrating sensory information to produce the desired output. Because of its simple nervous system and well-established neuronal connectome, C. elegans acts as an excellent model to understand the mechanisms underlying behavioral plasticity. Here, we critically review how neuropeptides modulate a wide range of behaviors by allowing for changes in neuronal and synaptic signaling. This review will have a specific focus on feeding, mating, sleep, addiction, learning and locomotory behaviors in C. elegans. With a view to understand evolutionary relationships, we explore the functions and associated pathophysiology of C. elegans neuropeptides that are conserved across different phyla. Further, we discuss the mechanisms of neuropeptidergic signaling and how these signals are regulated in different behaviors. Finally, we attempt to provide insight into developing potential therapeutics for neuropeptide-related disorders.

Distinct roles for Fgf, Wnt and retinoic acid in posteriorizing the neural ectoderm

Development ◽  
2002 ◽  
Vol 129 (18) ◽  
pp. 4335-4346 ◽  
Author(s):  
Tetsuhiro Kudoh ◽  
Stephen W. Wilson ◽  
Igor B. Dawid
Keyword(s):  
Retinoic Acid ◽  
Neural Plate ◽  
Neural Patterning ◽  
Knock Down ◽  
Complementary Pattern ◽  
Neural Ectoderm ◽  
Morpholino Oligonucleotides ◽  
And Function

Early neural patterning in vertebrates involves signals that inhibit anterior (A) and promote posterior (P) positional values within the nascent neural plate. In this study, we have investigated the contributions of, and interactions between, retinoic acid (RA), Fgf and Wnt signals in the promotion of posterior fates in the ectoderm. We analyze expression and function of cyp26/P450RAI, a gene that encodes retinoic acid 4-hydroxylase, as a tool for investigating these events. Cyp26 is first expressed in the presumptive anterior neural ectoderm and the blastoderm margin at the late blastula. When the posterior neural gene hoxb1b is expressed during gastrulation, it shows a strikingly complementary pattern to cyp26. Using these two genes, as well as otx2 and meis3 as anterior and posterior markers, we show that Fgf and Wnt signals suppress expression of anterior genes, including cyp26. Overexpression of cyp26 suppresses posterior genes, suggesting that the anterior expression of cyp26 is important for restricting the expression of posterior genes. Consistent with this, knock-down of cyp26 by morpholino oligonucleotides leads to the anterior expansion of posterior genes. We further show that Fgf- and Wnt-dependent activation of posterior genes is mediated by RA, whereas suppression of anterior genes does not depend on RA signaling. Fgf and Wnt signals suppress cyp26 expression, while Cyp26 suppresses the RA signal. Thus, cyp26 has an important role in linking the Fgf, Wnt and RA signals to regulate AP patterning of the neural ectoderm in the late blastula to gastrula embryo in zebrafish.

Features of morphological changes in the intramural nervous system of the heart in atherosclerosis and myocardial infarction

1980 ◽  
Vol 61 (4) ◽  
pp. 26-28
Author(s):  
M. V. Uglova ◽  
V. N. Shlyapnikov ◽  
V. V. Sergeev ◽  
A. U. Zalmunin ◽  
E. A. Taikov
Keyword(s):  
Myocardial Infarction ◽  
Nervous System ◽  
Morphological Changes ◽  
Morphometric Study ◽  
Hypertrophic Changes

Morphometric study of human cardiac neurocytes in myocardial infarction and atherosclerosis made it possible to establish that myocardial infarction causes adaptive (hypertrophic) changes in the intramural nervous system of the heart, especially pronounced on the first day of the course of the infarction; with atherosclerosis, the changes are characterized by a direction towards atrophic processes.

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