scholarly journals Drosophila Fragile X Protein, DFXR, Regulates Neuronal Morphology and Function in the Brain

Neuron ◽  
2002 ◽  
Vol 34 (6) ◽  
pp. 961-972 ◽  
Author(s):  
Joannella Morales ◽  
P.Robin Hiesinger ◽  
Andrew J. Schroeder ◽  
Kazuhiko Kume ◽  
Patrik Verstreken ◽  
...  
Keyword(s):  
Fragile X ◽  
Neuronal Morphology ◽  
X Protein ◽  
And Function ◽  
The Brain

scholarly journals Fragile X syndrome patient-derived neurons developing in the mouse brain show FMR1 -dependent phenotypes

2021 ◽  
Author(s):  
Marine A Krzisch ◽  
Hao A Wu ◽  
Bingbing Yuan ◽  
Troy W. Whitfield ◽  
X. Shawn Liu ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Neuronal Development ◽  
Fragile X ◽  
In Vitro Models ◽  
Synaptic Activity ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
And Function ◽  
The Brain

Abnormal neuronal development in Fragile X syndrome (FXS) is poorly understood. Data on FXS patients remain scarce and FXS animal models have failed to yield successful therapies. In vitro models do not fully recapitulate the morphology and function of human neurons. Here, we co-injected neural precursor cells (NPCs) from FXS patient-derived and corrected isogenic control induced pluripotent stem cells into the brain of neonatal immune-deprived mice. The transplanted cells populated the brain and a proportion differentiated into neurons and glial cells. Single-cell RNA sequencing of transplanted cells revealed upregulated excitatory synaptic transmission and neuronal differentiation pathways in FXS neurons. Immunofluorescence analyses showed accelerated maturation of FXS neurons after an initial delay. Additionally, increased percentages of Arc- and Egr1-positive FXS neurons and wider dendritic protrusions of mature FXS striatal medium spiny neurons pointed to an increase in synaptic activity and synaptic strength as compared to control. This transplantation approach provides new insights into the alterations of neuronal development in FXS by facilitating physiological development of cells in a 3D context, and could be used to test new therapeutic compounds correcting neuronal development defects in FXS.

scholarly journals Novel Role for the Nuclear Phosphoprotein SET in Transcriptional Activation of P450c17 and Initiation of Neurosteroidogenesis

2000 ◽  
Vol 14 (6) ◽  
pp. 875-888 ◽  
Author(s):  
Nathalie A. Compagnone ◽  
Peilin Zhang ◽  
Jean-Louis Vigne ◽  
Synthia H. Mellon
Keyword(s):  
Transcriptional Activation ◽  
Neuronal Morphology ◽  
Steroidogenic Factor 1 ◽  
Mouse Fetus ◽  
Neuronal Precursor Cells ◽  
Endogenous Regulators ◽  
Nuclear Phosphoprotein ◽  
Inducible Protein ◽  
And Function ◽  
The Brain

Abstract Neurosteroids are important endogenous regulators of γ-aminobutryic acid (GABAA) and N-methyl-d-aspartate (NMDA) receptors and also influence neuronal morphology and function. Neurosteroids are produced in the brain using many of the same enzymes found in the adrenal and gonad. The crucial enzyme for the synthesis of DHEA (dehydroepiandrosterone) in the brain is cytochrome P450c17. The transcriptional strategy for the expression of P450c17 is clearly different in the brain from that in the adrenal or gonad. We previously characterized a novel transcriptional regulator from Leydig MA-10 cells, termed StF-IT-1, that binds at bases −447/−399 of the rat P450c17 promoter, along with the known transcription factors COUP-TF (chicken ovalbumin upstream promoter transcription factor), NGF-IB (nerve growth factor inducible protein B), and SF-1 (steroidogenic factor-1). We have now purified and sequenced this protein from immature porcine testes, identifying it as the nuclear phosphoprotein SET; a role for SET in transcription was not established previously. Binding of bacterially expressed human and rat SET to the DNA site at −418/−399 of the rat P450c17 gene transactivates P450c17 in neuronal and in testicular Leydig cells. We also found SET expressed in human NT2 neuronal precursor cells, implicating a role in neurosteroidogenesis. Immunocytochemistry and in situ hybridization in the mouse fetus show that the ontogeny and distribution of SET in the developing nervous system are consistent with SET being crucial for initiating P450c17 transcription. SET’s developmental pattern of expression suggests it may participate in the early ontogenesis of the nervous, as well as the skeletal and hematopoietic, systems. These studies delineate an important new factor in the transcriptional regulation of P450c17 and consequently, in the production of DHEA and sex steroids.

scholarly journals Typical and atypical brain development: a review of neuroimaging studies

2013 ◽  
Vol 15 (3) ◽  
pp. 359-384 ◽  
Keyword(s):  
Brain Development ◽  
Neurodevelopmental Disorders ◽  
Fragile X ◽  
Early Adulthood ◽  
22Q11.2 Deletion Syndrome ◽  
Developmental Trajectory ◽  
Deletion Syndrome ◽  
Effective Interventions ◽  
And Function ◽  
The Brain

In the course of development, the brain undergoes a remarkable process of restructuring as it adapts to the environment and becomes more efficient in processing information. A variety of brain imaging methods can be used to probe how anatomy, connectivity, and function change in the developing brain. Here we review recent discoveries regarding these brain changes in both typically developing individuals and individuals with neurodevelopmental disorders. We begin with typical development, summarizing research on changes in regional brain volume and tissue density, cortical thickness, white matter integrity, and functional connectivity. Space limits preclude the coverage of all neurodevelopmental disorders; instead, we cover a representative selection of studies examining neural correlates of autism, attention deficit/hyperactivity disorder, Fragile X, 22q11.2 deletion syndrome, Williams syndrome, Down syndrome, and Turner syndrome. Where possible, we focus on studies that identify an age by diagnosis interaction, suggesting an altered developmental trajectory. The studies we review generally cover the developmental period from infancy to early adulthood. Great progress has been made over the last 20 years in mapping how the brain matures with MR technology. With ever-improving technology, we expect this progress to accelerate, offering a deeper understanding of brain development, and more effective interventions for neurodevelopmental disorders.

Rough Motor Development of Children with Intellectual Disabilities Age 8-10 Years

2020 ◽  
Vol 3 (3) ◽  
pp. 36-42
Author(s):  
Andres Amin
Keyword(s):  
Intellectual Disability ◽  
Intellectual Disabilities ◽  
Motor Development ◽  
Fragile X ◽  
Fetal Alcohol ◽  
Normal Children ◽  
Analysis Techniques ◽  
Hard Time ◽  
And Function ◽  
The Brain

Intellectual disability is a term used when there are limits to a person’s ability to learn at an expected level and function in daily life. Levels of intellectual disability vary greatly in children. Children with intellectual disability might have a hard time letting others know their wants and needs, and taking care of themselves. Intellectual disability could cause a child to learn and develop more slowly than other children of the same age. It could take longer for a child with intellectual disability to learn to speak, walk, dress, or eat without help, and they could have trouble learning in school. Intellectual disability can be caused by a problem that starts any time before a child turns 18 years old – even before birth. It can be caused by injury, disease, or a problem in the brain. For many children, the cause of their intellectual disability is not known. Some of the most common known causes of intellectual disability – like Down syndrome, fetal alcohol syndrome, fragile X syndrome, genetic conditions, birth defects, and infections – happen before birth. Others happen while a baby is being born or soon after birth. Still other causes of intellectual disability do not occur until a child is older; these might include serious head injury, stroke, or certain infections. This study aims to determine the development of gross motor in children with intellectual disabilities age 8-10 years. This research was conducted at SLB Negeri Surakarta. Data collection techniques such as interviews, observation and documentation. Data analysis techniques use descriptive qualitative using the Miles and Huberman model. Based on the results of this research is that some children with intellectual disabilities age 8-10 years of age experiencing no physical abnormalities, they also have problems in walking, running, jumping, balance, turning, bending, throwing, catching, and kicking. Thus it can be seen that the motor development of children with intellectual disabilities age 8-10 years are under normal children. This is due to the intelligence of the under-femoral child who is under 70/75 so that they have difficulty in coordinating the movement.

scholarly journals critical role of astrogenesis and neurodevelopment in Fragile X Syndrome and Rett Syndrome

2020 ◽  
Vol 17 (1) ◽  
Author(s):  
John Paul Oliveria ◽  
Zhuo Jun Li
Keyword(s):  
Fragile X Syndrome ◽  
Rett Syndrome ◽  
Fragile X ◽  
Critical Role ◽  
Notch Pathway ◽  
Janus Kinase ◽  
Future Research ◽  
Genetic Mutations ◽  
And Function ◽  
The Brain

Astrocytes play an important role in the development of functional neural circuits in the brain. They are responsible for coordinating synapse formation and function, axon guidance, and ensuring neuronal survival. Normal astrogenesis begins during late gestation. Neural stem cells (NSCs) become primarily gliogenic and differentiate to become astrocyte precursors. Through local proliferation and functional maturation, the precursors develop into mature astrocytes, which can either be fibrous or protoplasmic. Astrogenesis is regulated by both cell intrinsic programs and cell extrinsic cues. Intrinsic chromatin changes, such as demethylation of astrocyte-specific genes, allows the NSCs to become responsive to astrocyte-inducing exogenous cues. These cues involve a collaboration of multiple pathways, namely the Notch pathway, the bone morphogenetic protein (BMP) signaling pathway, interleukin-6 (IL-6) signaling, and the Janus Kinase/Signal Transducer and Activator of Transcription (JAK-STAT) pathway. Together, they allow for normal astrogenesis to occur. However, disruption to these pathways lead to abnormal astrocyte development and results in pathologies such as the Fragile X Syndrome (FXS) and Rett Syndrome (RS). Both neurodevelopmental disorders are a result of genetic mutations that causes either transcriptional silence or transcriptional activation at inappropriate stages during development. These genetic mutations result in depressed astrocyte function in FXS, and the overexcitement of astrocytes in RS. The current hypothesis under investigation is that altered gene transcription during neurodevelopment disrupts astrogenesis, and subsequently, the behavior and function of mature astrocytes in the brain. Future research should focus on understanding the timing of the transition from neurogenesis to astrogenesis and identifying astrocyte-specific markers that are critical to its function in neurodevelopment.

Human-mouse chimeric Fragile X syndrome model reveals FMR1-dependent neuronal phenotypes

2020 ◽  
Author(s):  
Marine Krzisch ◽  
Hao Wu ◽  
Bingbing Yuan ◽  
Troy Whitfield ◽  
Shawn Liu ◽  
...  
Keyword(s):  
Fragile X Syndrome ◽  
Neuronal Development ◽  
Fragile X ◽  
In Vitro Models ◽  
Synaptic Activity ◽  
Human Neurons ◽  
Induced Pluripotent ◽  
And Function ◽  
The Brain

Abstract Abnormal neuronal development in Fragile X syndrome (FXS) is poorly understood. Data on FXS patients remain scarce and FXS animal models have failed to yield successful therapies. In vitro models do not fully recapitulate the morphology and function of human neurons. Here, we co-injected neural precursor cells (NPCs) from FXS patient-derived and corrected isogenic control induced pluripotent stem cells into the brain of neonatal immune-deprived mice. The cells populated the brain and differentiated into neurons and astrocytes. Single-cell RNA sequencing of transplanted cells revealed upregulated excitatory synaptic transmission and neuronal differentiation pathways in FXS neurons. Immunofluorescence analyses showed accelerated maturation of FXS neurons, an increased proportion of Arc-positive FXS neurons and increased dendritic protrusion width of FXS striatal medium spiny neurons. Our data show faster maturation and suggest increased synaptic activity and synaptic strength of FXS transplanted neurons. This model provides new insights into the alterations in FXS neuronal development.

Ultrastructure of developing visual cortical synapses in the cat superior colliculus

1991 ◽  
Vol 49 ◽  
pp. 156-157
Author(s):  
Caroline A. Miller ◽  
Laura L. Bruce
Keyword(s):  
Superior Colliculus ◽  
Phosphate Buffer ◽  
Receptive Fields ◽  
Visual Cortical Area ◽  
Cortical Synapses ◽  
Visual Cortical ◽  
And Function ◽  
Phosphate Buffered Saline ◽  
The Brain ◽  
Cat Superior Colliculus

The first visual cortical axons arrive in the cat superior colliculus by the time of birth. Adultlike receptive fields develop slowly over several weeks following birth. The developing cortical axons go through a sequence of changes before acquiring their adultlike morphology and function. To determine how these axons interact with neurons in the colliculus, cortico-collicular axons were labeled with biocytin (an anterograde neuronal tracer) and studied with electron microscopy.Deeply anesthetized animals received 200-500 nl injections of biocytin (Sigma; 5% in phosphate buffer) in the lateral suprasylvian visual cortical area. After a 24 hr survival time, the animals were deeply anesthetized and perfused with 0.9% phosphate buffered saline followed by fixation with a solution of 1.25% glutaraldehyde and 1.0% paraformaldehyde in 0.1M phosphate buffer. The brain was sectioned transversely on a vibratome at 50 μm. The tissue was processed immediately to visualize the biocytin.

Revision Targeted Muscle Reinnervation Improves Secondary Pain Insult in an Upper Extremity Amputee: A Case Report

Hand ◽  
2021 ◽  
pp. 155894472199246
Author(s):  
David D. Rivedal ◽  
Meng Guo ◽  
James Sanger ◽  
Aaron Morgan
Keyword(s):  
Neuropathic Pain ◽  
Peripheral Nerves ◽  
Nerve Biopsy ◽  
Sensory Cortex ◽  
Denervated Muscle ◽  
Unique Case ◽  
Targeted Muscle Reinnervation ◽  
Muscle Reinnervation ◽  
And Function ◽  
The Brain

Targeted muscle reinnervation (TMR) has been shown to improve phantom and neuropathic pain in both the acute and chronic amputee population. Through rerouting of major peripheral nerves into a newly denervated muscle, TMR harnesses the plasticity of the brain, helping to revert the sensory cortex back toward the preinsult state, effectively reducing pain. We highlight a unique case of an above-elbow amputee for sarcoma who was initially treated with successful transhumeral TMR. Following inadvertent nerve biopsy of a TMR coaptation site, his pain returned, and he was unable to don his prosthetic. Revision of his TMR to a more proximal level was performed, providing improved pain and function of the amputated arm. This is the first report to highlight the concept of secondary neuroplasticity and successful proximal TMR revision in the setting of multiple insults to the same extremity.

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