scholarly journals The specification of noradrenergic locus coeruleus (LC) neurones depends on bone morphogenetic proteins (BMPs)

Development ◽  
2002 ◽  
Vol 129 (4) ◽  
pp. 983-991 ◽  
Author(s):  
Astrid Vogel-Höpker ◽  
Hermann Rohrer
Keyword(s):  
Transcription Factors ◽  
Locus Coeruleus ◽  
Bone Morphogenetic Proteins ◽  
Chick Embryos ◽  
Dorsal Midline ◽  
Neural Crest Development ◽  
Roof Plate ◽  
Rhombic Lip ◽  
The Brain

The role of BMPs in the development of the major noradrenergic centre of the brain, the locus coeruleus (LC), was investigated. LC generation is reflected by initial expression of the transcription factors Phox2a and Phox2b in dorsal rhombomere1 (r1), followed by expression of dopamine-β-hydroxylase and tyrosine hydroxylase. Bmp5 is expressed in the dorsal neuroepithelium in proximity to Phox2-expressing cells. BMP inhibition in stage 10 chick embryos resulted in the lack of LC neurones or in their generation at the dorsal midline, and loss of roof plate and rhombic lip, but it did not affect neural crest development. These results reveal late essential BMP functions in the specification of dorsal neuronal phenotypes in r1, including LC neurones, and in the development of dorsal midline structures.

The Effect of Chloroacetophenone on Chick Embryos Cultured in vitro

Development ◽  
1962 ◽  
Vol 10 (3) ◽  
pp. 373-382
Author(s):  
M. S. Lakshmi
Keyword(s):  
Xenopus Laevis ◽  
Average Length ◽  
Primitive Streak ◽  
Poultry Farm ◽  
Chick Embryos ◽  
Normal Process ◽  
Strong Emphasis ◽  
The Brain

Brachet's (1950) strong emphasis on the role of —SH-containing proteins in the process of induction has stimulated a study of the interference in the normal process of morphogenesis of chick embryos by chloroacetophenone, which has been described by Beatty (1951) as a specific and irreversible —SH inhibitor. He studied the effect of chloroacetophenone on the development of embryos of Rana and Triturus employing different concentrations. Deuchar (1957) also studied the action of the same chemical on the embryos of Xenopus laevis and has recorded abnormalities mainly in the brain and the eye. In the present work ω-chloroacetophenone (CAP) commercially known as phenacyl chloride (ω—C6H5.CO.CH2Cl) was employed. The sample used was a B.D.H. product. Fresh fertilized hens' eggs brought from a local poultry farm were incubated at 37·5° C. for 16 to 18 hours to obtain definitive primitive-streak stages (range of length from 1·75 mm. to 2 mm.) or for about 22 hours to obtain head-process stages (average length of the head process alone 0·56 mm.).

scholarly journals Enhanced aversive memory retrieval by chemogenetic activation of locus coeruleus norepinephrine neurons

2019 ◽  
Author(s):  
Ryoji Fukabori ◽  
Yoshio Iguchi ◽  
Shigeki Kato ◽  
Kazumi Takahashi ◽  
Satoshi Eifuku ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Memory Retrieval ◽  
Adrenergic Receptors ◽  
Retrieval Process ◽  
Memory Store ◽  
Facilitative Role ◽  
Pharmacological Blockade ◽  
The Brain ◽  
Stimulation Of

AbstractThe ability to retrieve memory store in response to the environment is essential for animal behavioral adaptation. Norepinephrine (NE)-containing neurons in the brain play a key role in the modulation of synaptic plasticity underlying various processes of memory formation. However, the role of the central NE system in memory retrieval remains unclear. In this study, we developed a neural chemogenetic activation strategy using insect olfactory Ionotropic Receptors (IRs), and used it for selective stimulation of NE neurons in the locus coeruleus (LC) in transgenic mice. Ligand-induced activation of LC NE neurons resulted in enhancement of the retrieval process of conditioned taste aversion, which was mediated through at least partly adrenergic receptors in the amygdala. Pharmacological blockade of LC activity confirmed the facilitative role of these neurons in memory retrieval. Our findings indicate that the LC-amygdalar pathway is required and sufficient for enhancing the recall of taste associative memory.

scholarly journals Generation of the squamous epithelial roof of the 4th ventricle

2018 ◽  
Author(s):  
Florent Campo-Paysaa ◽  
Jonathan DW Clarke ◽  
Richard JT Wingate
Keyword(s):  
Cell Fate ◽  
Squamous Epithelium ◽  
De Novo ◽  
Dorsal Midline ◽  
Direct Transformation ◽  
Squamous Cells ◽  
Roof Plate ◽  
The Veil ◽  
Rhombic Lip ◽  
4Th Ventricle

SummaryWe use the transparency of zebrafish embryos to reveal the de novo generation of a simple squamous epithelium and identify the cellular architecture in the epithelial transition zone that ties this squamous epithelium to the columnar neuroepithelium within the embryo’s brain. The simple squamous epithelium of the rhombencephalic roof plate is pioneered by distinct mesenchymal cells at the dorsal midline of the neural tube. Subsequently a progenitor zone is established at the interface between columnar epithelium of the rhombic lip and the expanding squamous epithelium of the roof plate. Surprisingly this interface consists of a single progenitor cell type that we have named the veil cell. Veil cells express gdf6a and constitute a lineage restricted stem zone that generates the squamous roof plate by direct transformation and asymmetrically fated divisions. Experimental restriction of roof plate expansion leads to extrusion of veil cell daughters and squamous cells, suggesting veil cell fate is regulated by the space available for roof plate growth.

scholarly journals Generation of the squamous epithelial roof of the 4th ventricle

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Florent Campo-Paysaa ◽  
Jonathan DW Clarke ◽  
Richard JT Wingate
Keyword(s):  
Cell Fate ◽  
Squamous Epithelium ◽  
De Novo ◽  
Dorsal Midline ◽  
Direct Transformation ◽  
Squamous Cells ◽  
Roof Plate ◽  
The Veil ◽  
Rhombic Lip ◽  
4Th Ventricle

We use the transparency of zebrafish embryos to reveal the de novo generation of a simple squamous epithelium and identify the cellular architecture in the epithelial transition zone that ties this squamous epithelium to the columnar neuroepithelium within the embryo's brain. The simple squamous epithelium of the rhombencephalic roof plate is pioneered by distinct mesenchymal cells at the dorsal midline of the neural tube. Subsequently, a progenitor zone is established at the interface between columnar epithelium of the rhombic lip and the expanding squamous epithelium of the roof plate. Surprisingly, this interface consists of a single progenitor cell type that we have named the veil cell. Veil cells express gdf6a and constitute a lineage restricted stem zone that generates the squamous roof plate by direct transformation and asymmetrically fated divisions. Experimental restriction of roof plate expansion leads to extrusion of veil cell daughters and squamous cells, suggesting veil cell fate is regulated by the space available for roof plate growth.

Role of Forkhead Transcription Factors of the O Class (FoxO) in Development and Progression of Alzheimer’s Disease

2020 ◽  
Vol 19 (9) ◽  
pp. 709-721
Author(s):  
Shikha Goswami ◽  
Ozaifa Kareem ◽  
Ramesh K. Goyal ◽  
Sayed M. Mumtaz ◽  
Rajiv K. Tonk ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Transcription Factors ◽  
Neurological Disorders ◽  
The United States ◽  
Forkhead Transcription Factors ◽  
The Central Nervous System ◽  
Degenerative Disorder ◽  
The Brain

: In the central nervous system (CNS), a specific loss of focal neurons leads to mental and neurological disorders like dementia, Alzheimer’s disease (AD), Huntington’s disease, Parkinson’s disease, etc. AD is a neurological degenerative disorder, which is progressive and irreversible in nature and is the widely recognized reason for dementia in the geriatric populace. It affects 10% of people above the age of 65 and is the fourth driving reason for death in the United States. Numerous evidence suggests that the neuronal compartment is not the only genesis of AD, but transcription factors also hold significant importance in the occurrence and advancement of the disease. It is the need of the time to find the novel molecular targets and new techniques for treating or slowing down the progression of neurological disorders, especially AD. In this article, we summarised a conceivable association between transcriptional factors and their defensive measures against neurodegeneration and AD. The mammalian forkhead transcription factors of the class O (FoxO) illustrate one of the potential objectives for the development of new methodologies against AD and other neurocognitive disorders. The presence of FoxO is easily noticeable in the “cognitive centers” of the brain, specifically in the amygdala, hippocampus, and the nucleus accumbens. FoxO proteins are the prominent and necessary factors in memory formation and cognitive functions. FoxO also assumes a pertinent role in the protection of multiple cells in the brain by controlling the involving mechanism of autophagy and apoptosis and also modulates the process of phosphorylation of the targeted protein, thus FoxO must be a putative target in the mitigation of AD. This review features the role of FoxO as an important biomarker and potential new targets for the treatment of AD.

scholarly journals Melatonin and Melatonergic Influence on Neuronal Transcription Factors: Implications for the Development of Novel Therapies for Neurodegenerative Disorders

2020 ◽  
Vol 18 (7) ◽  
pp. 563-577
Author(s):  
O.J. Onaolapo ◽  
A.Y. Onaolapo ◽  
O.A. Olowe ◽  
M.O. Udoh ◽  
D.O. Udoh ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Neurodegenerative Disorders ◽  
Scientific Literature ◽  
Experimental Studies ◽  
Cell Multiplication ◽  
Therapeutic Implications ◽  
Signalling Molecule ◽  
Mammalian Pineal Gland ◽  
The Brain

Melatonin is a multifunctional signalling molecule that is secreted by the mammalian pineal gland, and also found in a number of organisms including plants and bacteria. Research has continued to uncover an ever-increasing number of processes in which melatonin is known to play crucial roles in mammals. Amongst these functions is its contribution to cell multiplication, differentiation and survival in the brain. Experimental studies show that melatonin can achieve these functions by influencing transcription factors which control neuronal and glial gene expression. Since neuronal survival and differentiation are processes that are important determinants of the pathogenesis, course and outcome of neurodegenerative disorders; the known and potential influences of melatonin on neuronal and glial transcription factors are worthy of constant examination. In this review, relevant scientific literature on the role of melatonin in preventing or altering the course and outcome of neurodegenerative disorders, by focusing on melatonin’s influence on transcription factors is examined. A number of transcription factors whose functions can be influenced by melatonin in neurodegenerative disease models have also been highlighted. Finally, the therapeutic implications of melatonin’s influences have also been discussed and the potential limitations to its applications have been highlighted.

scholarly journals STUDIES ON THE PSITTACOSIS-LYMPHOGRANULOMA GROUP

1953 ◽  
Vol 97 (6) ◽  
pp. 783-795 ◽  
Author(s):  
Emma G. Allen ◽  
Anthony J. Girardi ◽  
M. Michael Sigel ◽  
Morton Klein
Keyword(s):  
Virus Multiplication ◽  
Host Tissue ◽  
Time Interval ◽  
Chick Embryos ◽  
Virus Inoculation ◽  
Virus Growth ◽  
Inhibition Of Growth ◽  
The Brain ◽  
Direct Adsorption

The findings presented indicate that aureomycin could become associated with tissue of the chick embryo by both hematogenous distribution and direct adsorption. Treatment of chick embryos infected with MP virus with 1 mg. of aureomycin by the allantoic route caused an inhibition of virus growth in the allantoic membrane. The drug had no effect on "inert" virus, and appeared to have little effect on adsorption of virus to host tissue. Complete inhibition of growth during the time interval corresponding to the first cycle of multiplication could be achieved only if the drug was administered within 6 to 8 hours after virus inoculation. Partial inhibition of virus multiplication could be achieved even if the administration was delayed as late as 24 hours after infection. In these experiments the chief role of the antibiotic appeared to be one of virustasis reflected in a prolongation of the latent period (non-infectious phase). The virus was able to resume its growth when a critical low level of the drug in the allantoic membrane was reached. When infectivity titrations were carried out using various tissues and organs of treated and untreated embryos, it was found that no virus was detectable in the brains of treated embryos as late as 192 hours after inoculation of virus. This was in contrast with the findings in allantoic membranes and livers of such embryos; these organs showed virus at 120 and 144 hours, respectively. In untreated controls, virus appeared in membranes at 24 hours, in the liver at 48 hours, and in the brain at 72 hours.

scholarly journals Intrinsic braking role of descending locus coeruleus noradrenergic neurons in acute and chronic itch in mice

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Keisuke Koga ◽  
Yuto Shiraishi ◽  
Ryo Yamagata ◽  
Hidetoshi Tozaki-Saitoh ◽  
Miho Shiratori-Hayashi ◽  
...  
Keyword(s):  
Locus Coeruleus ◽  
Noradrenergic Neurons ◽  
Cell Type ◽  
Patch Clamp Recording ◽  
Peptide Receptor ◽  
Gastrin Releasing Peptide ◽  
Unpleasant Sensation ◽  
Chronic Itch ◽  
The Brain

Abstract Itch is defined as an unpleasant sensation that provokes a desire to scratch. Our understanding of neuronal circuits for itch information transmission and processing in the spinal dorsal horn (SDH) has progressively advanced following the identification of SDH neuron subsets that are crucial for scratching behavior in models of itch. However, little is known about the control of acute and chronic itch by descending signals from the brain to the SDH. In this study, using genetic approaches that enable cell-type and circuit-specific functional manipulation, we reveal an intrinsic potential of locus coeruleus (LC)-noradrenergic (NAergic) neurons that project to the SDH to control acute and chronic itch. Activation and silencing of SDH-projecting LC-NAergic neurons reduced and enhanced scratching behavior, respectively, in models of histamine-dependent and -independent acute itch. Furthermore, in a model of chronic itch associated with contact dermatitis, repetitive scratching behavior was suppressed by the activation of the descending LC-NAergic pathway and by knocking out NA transporters specific to descending LC-NAergic neurons using a CRISPR-Cas9 system. Moreover, patch-clamp recording using spinal slices showed that noradrenaline facilitated inhibitory synaptic inputs onto gastrin-releasing peptide receptor-expressing SDH neurons, a neuronal subset known to be essential for itch transmission. Our findings suggest that descending LC-NAergic signaling intrinsically controls acute and chronic itch and provide potential therapeutic strategies for the treatment of acute and chronic itch.

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