The expansion of the human family, resulting in a human-specific paralog likely contributed to altered evolutionary brain features. The introduction of in mouse models is associated with changes in cortical neuronal migration, axon guidance, synaptogenesis, and sensory-task performance. Truncated SRGAP2C heterodimerizes with the full-length ancestral gene product SRGAP2A and antagonizes its functions.
View Article and Find Full Text PDFAdult neurogenesis persists in mammals in the neurogenic zones, where newborn neurons are incorporated into preexisting circuits to preserve and improve learning and memory tasks. Relevant structural elements of the neurogenic niches include the family of cell adhesion molecules (CAMs), which participate in signal transduction and regulate the survival, division, and differentiation of radial glial progenitors (RGPs). Here we analyzed the functions of neural cell adhesion molecule 2 (NCAM2) in the regulation of RGPs in adult neurogenesis and during corticogenesis.
View Article and Find Full Text PDFLysosomes communicate through cholesterol transfer at endoplasmic reticulum (ER) contact sites. At these sites, the Niemann Pick C1 cholesterol transporter (NPC1) facilitates the removal of cholesterol from lysosomes, which is then transferred to the ER for distribution to other cell membranes. Mutations in NPC1 result in cholesterol buildup within lysosomes, leading to Niemann-Pick Type C (NPC) disease, a progressive and fatal neurodegenerative disorder.
View Article and Find Full Text PDFThe central nervous system contains a myriad of different cell types produced from multipotent neural progenitors. Neural progenitors acquire distinct cell identities depending on their spatial position, but they are also influenced by temporal cues to give rise to different cell populations over time. For instance, the progenitors of the cerebral neocortex generate different populations of excitatory projection neurons following a well-known sequence.
View Article and Find Full Text PDFThe dentate gyrus (DG) is an essential part of the hippocampal formation and participates in the majority of hippocampal functions. The DG is also one of the few structures in the mammalian central nervous system that produces adult-born neurons and, in humans, alterations in adult neurogenesis are associated with stress and depression. Given the importance of DG in hippocampal function, it is imperative to understand the molecular mechanisms driving DG development and homeostasis.
View Article and Find Full Text PDFTracking and quantifying the abundance and location of cells in the developing brain is essential in neuroscience research, enabling a greater understanding of mechanisms underlying nervous system morphogenesis. Widely used experimental methods to quantify cells labeled with fluorescent markers, such as immunohistochemistry (IHC), hybridization, and expression of transgenes via stable lines or transient electroporations (IUEs), depend on accurate and consistent quantification of images. Current methods to quantify fluorescently-labeled cells rely on labor-intensive manual counting approaches, such as the Fiji plugin , which requires custom macros to enable higher-throughput analyses.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
October 2021
Ca is the most ubiquitous second messenger in neurons whose spatial and temporal elevations are tightly controlled to initiate and orchestrate diverse intracellular signaling cascades. Numerous neuropathologies result from mutations or alterations in Ca handling proteins; thus, elucidating molecular pathways that shape Ca signaling is imperative. Here, we report that loss-of-function, knockout, or neurodegenerative disease-causing mutations in the lysosomal cholesterol transporter, Niemann-Pick Type C1 (NPC1), initiate a damaging signaling cascade that alters the expression and nanoscale distribution of IPR type 1 (IPR1) in endoplasmic reticulum membranes.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
September 2020
The small GTPase ARL4C participates in the regulation of cell migration, cytoskeletal rearrangements, and vesicular trafficking in epithelial cells. The ARL4C signaling cascade starts by the recruitment of the ARF-GEF cytohesins to the plasma membrane, which, in turn, bind and activate the small GTPase ARF6. However, the role of ARL4C-cytohesin-ARF6 signaling during hippocampal development remains elusive.
View Article and Find Full Text PDFNeural cell adhesion molecule 2 (NCAM2) is involved in the development and plasticity of the olfactory system. Genetic data have implicated the NCAM2 gene in neurodevelopmental disorders including Down syndrome and autism, although its role in cortical development is unknown. Here, we show that while overexpression of NCAM2 in hippocampal neurons leads to minor alterations, its downregulation severely compromises dendritic architecture, leading to an aberrant phenotype including shorter dendritic trees, retraction of dendrites, and emergence of numerous somatic neurites.
View Article and Find Full Text PDFIn the neural progenitors of the developing central nervous system (CNS), cell proliferation is tightly controlled and coordinated with cell fate decisions. Progenitors divide rapidly during early development and their cell cycle lengthens progressively as development advances to eventually give rise to a tissue of the correct size and cellular composition. However, our understanding of the molecules linking cell cycle progression to developmental time is incomplete.
View Article and Find Full Text PDFBackground: The E3 Cullin 5-RING ubiquitin ligase (CRL5) is a multiprotein complex that has recently been highlighted as a major regulator of central nervous system development. Cullin 5 (Cul5) and the RING finger protein Rbx2 are two CRL5 core components required for CRL5 function in the brain, but their full expression patterns and developmental functions have not been described in detail.
Results: Using a gene-trap mouse model for Cul5 and a knock-in-knockout mouse model for Rbx2, we show that lack of Cul5, but not Rbx2, disrupts blastocyst formation.
The laminated structure of the retina is fundamental for the organization of the synaptic circuitry that translates light input into patterns of action potentials. However, the molecular mechanisms underlying cell migration and layering of the retina are poorly understood. Here, we show that RBX2, a core component of the E3 ubiquitin ligase CRL5, is essential for retinal layering and function.
View Article and Find Full Text PDFObjective: Tuberous sclerosis complex (TSC) is often associated with cerebral tubers and medically intractable epilepsy. We reevaluated whether increased uptake of α-[(11) C]methyl-l-tryptophan (AMT) in cerebral tubers is associated with tuber epileptogenicity.
Methods: We included 12 patients (six male, 4-53 years old) with TSC and refractory seizures who were evaluated for epilepsy surgery in our center, including video-electroencephalographic (EEG) monitoring, fluid-attenuated inversion recovery magnetic resonance imaging (FLAIR MRI), and positron emission tomography (PET) with α-[(11) C]methyl-l-tryptophan (AMT-PET).
In this paper, through a detailed comparison between a translated book on nursing and its original American source, I examine the position of nursing in the mentality of a Japanese doctor at the beginning of the Meiji Era. In 1877, Dr. Yunei Ota published a translated version of a book on nursing titled "Kango-Kokoroe.
View Article and Find Full Text PDFBiosci Biotechnol Biochem
October 2006
We examined the dietary effects of cyclic nigerosylnigerose (CNN), a dietary indigestible oligosaccharide with four D-glucopyranosyl residues linked by alternating alpha-(1-->3)- and alpha-(1-->6) glucosidic linkages, on the intestinal immune function of mice, and the effects were compared with those of alpha-(1-->3)-linked oligosaccharide (nigerooligosaccharides, NOS) or alpha-(1-->6)-linked oligosaccharide (isomaltooligosaccharides, IMO). BALB/c mice were fed with 1-5% CNN, 5% IMO, or 12.5% NOS for 4 weeks, and the intestinal mucosal immune responses were determined.
View Article and Find Full Text PDFBackground: It is necessary to decrease topical anti-glaucoma medication for severe glaucoma with pseudopemphigoid caused by anti-glaucoma eye drops. Glaucoma filtrating surgery is often needed instead of medication, but the prognosis is poor because it induces scar fomation and makes the filtrating bleb vanish.
Case: An 85-year-old male patient with exfoliation syndrome had twice undergone glaucoma surgery about ten years previously.
We have evaluated the effect of natural human interferon (IFN)-alpha on the growth of chlamydia trachomatis in human epithelial cells in vitro and revealed that IFN-alpha has reduced both growth and infectivity of C. trachomatis. The effect of IFN-alpha was reversed by the addition of exogenous L-tryptophan and iron to the culture medium, suggesting that antichlamydial effect of IFN-alpha was caused by depletion of intracellular tryptophan and iron, both of which are essential for chlamydial growth.
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