Cell Division and Migration in the Brain After Optic Nerve Lesions

2008 ◽  
pp. 53-76 ◽  
Author(s):  
R. M. Gazea ◽  
W. E. Watson
Keyword(s):  
Cell Division ◽  
Optic Nerve ◽  
Nerve Lesions ◽  
And Migration ◽  
The Brain

scholarly journals Endocrine Dysfunction in Children with Zika-Related Microcephaly Who Were Born during the 2015 Epidemic in the State of Pernambuco, Brazil

Viruses ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Andréia Veras Gonçalves ◽  
Demócrito de B. Miranda-Filho ◽  
Líbia Cristina Rocha Vilela ◽  
Regina Coeli Ferreira Ramos ◽  
Thalia V. B. de Araújo ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Viral Infections ◽  
Case Series ◽  
Optic Nerve Hypoplasia ◽  
Endocrine Dysfunction ◽  
Careful Monitoring ◽  
Early Puberty ◽  
Growth Impairment ◽  
Appropriate Treatment ◽  
The Brain

Congenital viral infections and the occurrence of septo-optic dysplasia, which is a combination of optic nerve hypoplasia, abnormal formation of structures along the midline of the brain, and pituitary hypofunction, support the biological plausibility of endocrine dysfunction in Zika-related microcephaly. In this case series we ascertained the presence and describe endocrine dysfunction in 30 children with severe Zika-related microcephaly from the MERG Pediatric Cohort, referred for endocrinological evaluation between February and August 2019. Of the 30 children, 97% had severe microcephaly. The average age at the endocrinological consultation was 41 months and 53% were female. The most frequently observed endocrine dysfunctions comprised short stature, hypothyroidism, obesity and variants early puberty. These dysfunctions occurred alone 57% or in combination 43%. We found optic nerve hypoplasia (6/21) and corpus callosum hypoplasia (20/21). Seizure crises were reported in 86% of the children. The most common—and clinically important—endocrine dysfunctions were pubertal dysfunctions, thyroid disease, growth impairment, and obesity. These dysfunctions require careful monitoring and signal the need for endocrinological evaluation in children with Zika-related microcephaly, in order to make early diagnoses and implement appropriate treatment when necessary.

A preliminary account of brain growth in postlarval Nereis virens (Polychaeta: Annelida): a [3H]thymidine study

1980 ◽  
Vol 58 (11) ◽  
pp. 2141-2149
Author(s):  
Jane Easdown ◽  
Joan Marsden ◽  
Khazal Paradis ◽  
Kathryn Bell ◽  
Judith Jost
Keyword(s):  
Cell Division ◽  
Brain Growth ◽  
Nereis Virens ◽  
Preliminary Account ◽  
Reduced Rate ◽  
The Brain

Labelling of the supraoesophageal ganglion of postlarval Nereis virens with [3H]thymidine indicates that cell division is most active in very small worms, less than 0.1 g in weight. In such animals a few, small, labelled neurons were found, but only after 13 h of exposure to isotope. After shorter exposures, very small, undifferentiated labelled cells were seen in most of the ganglionic areas of the brain, although the various ganglionic nuclei differ in the time of first appearance of their characteristic neurons. In older animals gliagenesis continues at a reduced rate and neuron production becomes extremely slow.

Retrobulbar optic neuritis due to diseases of the posterior sinuses

1927 ◽  
Vol 23 (9) ◽  
pp. 973-973
Author(s):  
N. A. Khristianov
Keyword(s):  
Optic Nerve ◽  
Optic Neuritis ◽  
Circulatory System ◽  
Nerve Lesions ◽  
Retrobulbar Optic Neuritis ◽  
Anatomical Connection

Close anatomical connection between the optic nerve and the posterior nasal appendages and the commonality of their circulatory system explain optic nerve lesions in purulent and catarrhal processes in the posterior sinuses. N.A. Khristianov describes a case of left-sided retrobulbar optic neuritis cured by opening the middle and posterior lattices of the same side, affected by chronic catarrh.

Retinal input influences pace of neurogenesis but not cell-type configuration of the visual forebrain

2021 ◽  
Author(s):  
Shachar Sherman ◽  
Koichi Kawakami ◽  
Herwig Baier
Keyword(s):  
Visual Information ◽  
Visual Stimulation ◽  
Ganglion Cells ◽  
Neuronal Cell ◽  
Cell Types ◽  
Vertebrate Brain ◽  
Relative Contribution ◽  
Retinal Input ◽  
And Migration ◽  
The Brain

The brain is assembled during development by both innate and experience-dependent mechanisms1-7, but the relative contribution of these factors is poorly understood. Axons of retinal ganglion cells (RGCs) connect the eye to the brain, forming a bottleneck for the transmission of visual information to central visual areas. RGCs secrete molecules from their axons that control proliferation, differentiation and migration of downstream components7-9. Spontaneously generated waves of retinal activity, but also intense visual stimulation, can entrain responses of RGCs10 and central neurons11-16. Here we asked how the cellular composition of central targets is altered in a vertebrate brain that is depleted of retinal input throughout development. For this, we first established a molecular catalog17 and gene expression atlas18 of neuronal subpopulations in the retinorecipient areas of larval zebrafish. We then searched for changes in lakritz (atoh7-) mutants, in which RGCs do not form19. Although individual forebrain-expressed genes are dysregulated in lakritz mutants, the complete set of 77 putative neuronal cell types in thalamus, pretectum and tectum are present. While neurogenesis and differentiation trajectories are overall unaltered, a greater proportion of cells remain in an uncommitted progenitor stage in the mutant. Optogenetic stimulation of a pretectal area20,21 evokes a visual behavior in blind mutants indistinguishable from wildtype. Our analysis shows that, in this vertebrate visual system, neurons are produced more slowly, but specified and wired up in a proper configuration in the absence of any retinal signals.

scholarly journals Photoreceptive retinal ganglion cells control the information rate of the optic nerve

2018 ◽  
Vol 115 (50) ◽  
pp. E11817-E11826 ◽  
Author(s):  
Nina Milosavljevic ◽  
Riccardo Storchi ◽  
Cyril G. Eleftheriou ◽  
Andrea Colins ◽  
Rasmus S. Petersen ◽  
...  
Keyword(s):  
Optic Nerve ◽  
Retinal Ganglion Cells ◽  
Information Flow ◽  
Information Transfer ◽  
Ganglion Cells ◽  
Retinal Ganglion ◽  
Ambient Light ◽  
Visual Responses ◽  
Light Irradiance ◽  
The Brain

Information transfer in the brain relies upon energetically expensive spiking activity of neurons. Rates of information flow should therefore be carefully optimized, but mechanisms to control this parameter are poorly understood. We address this deficit in the visual system, where ambient light (irradiance) is predictive of the amount of information reaching the eye and ask whether a neural measure of irradiance can therefore be used to proactively control information flow along the optic nerve. We first show that firing rates for the retina’s output neurons [retinal ganglion cells (RGCs)] scale with irradiance and are positively correlated with rates of information and the gain of visual responses. Irradiance modulates firing in the absence of any other visual signal confirming that this is a genuine response to changing ambient light. Irradiance-driven changes in firing are observed across the population of RGCs (including in both ON and OFF units) but are disrupted in mice lacking melanopsin [the photopigment of irradiance-coding intrinsically photosensitive RGCs (ipRGCs)] and can be induced under steady light exposure by chemogenetic activation of ipRGCs. Artificially elevating firing by chemogenetic excitation of ipRGCs is sufficient to increase information flow by increasing the gain of visual responses, indicating that enhanced firing is a cause of increased information transfer at higher irradiance. Our results establish a retinal circuitry driving changes in RGC firing as an active response to alterations in ambient light to adjust the amount of visual information transmitted to the brain.

scholarly journals BSCI-12. Inhibition of melanoma brain metastasis by targeting miR-146a

2021 ◽  
Vol 3 (Supplement_3) ◽  
pp. iii3-iii3
Author(s):  
Jiwei Wang ◽  
Emma Rigg ◽  
Taral R Lunavat ◽  
Wenjing Zhou ◽  
Zichao Feng ◽  
...  
Keyword(s):  
Brain Metastasis ◽  
Tumor Cells ◽  
Cell Lines ◽  
Western Blots ◽  
Cell Growth And Migration ◽  
Human Astrocytes ◽  
And Migration ◽  
The Brain

Abstract Background Melanoma has the highest propensity of any cancer to metastasize to the brain, with late-stage patients developing brain metastasis (MBM) in 40% of cases. Survival of patients with MBM is around 8 months with current therapies, illustrating the need for new treatments. MBM development is likely caused by molecular interactions between tumor cells and the brain, constituting the brain metastatic niche. miRNAs delivered by exosomes released by the primary tumor cells may play a role in niche establishment, yet the mechanisms are poorly understood. Here, the aim was to identify miRNAs released by exosomes from melanomas, which may be important in niche establishment and MBM progression. Materials and Methods miRNAs from exosomes collected from human astrocytes, melanocytes, and MBM cell lines were profiled to determine differential expression. Functional in vitro validation was performed by cell growth and migration assays, cytokine arrays, qPCR and Western blots. Functional in vivo studies were performed after miR knockdown in MBM cell lines. An in silico docking study was performed to determine drugs that potentially inhibit transcription of miR-146a to impede MBM development. Results miR-146a was the most upregulated miRNA in exosomes from MBM cells and was highly expressed in human and animal MBM samples. miR-146a mimics activated human astrocytes, shown by increased proliferation and migration, elevated expression of GFAP in vitro and in mouse brain tumor samples, and increased cytokine production. In animal studies, knockdown of miR-146a in MBM cells injected intracardially into mice reduced BM burden and increased animal survival. Based on the docking studies, deserpidine was found to be an effective inhibitor of MBM growth in vitro and in vivo. Conclusions MiR-146a may play an important role in MBM development, and deserpidine is a promising candidate for clinical use.

scholarly journals Ocular, Neurologic and Systemic Findings of the Cases with Optic Nerve Hypoplasia

2016 ◽  
Vol 10 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Eyyup Karahan ◽  
Ayse Tulin Berk
Keyword(s):  
Optic Nerve ◽  
Chart Review ◽  
Retrospective Chart Review ◽  
Optic Nerve Hypoplasia ◽  
Refractive Errors ◽  
Poor Vision ◽  
The Relationship ◽  
The Brain ◽  
Ocular Signs ◽  
Neurologic Findings

Aim: To describe the associated ocular, neurologic, and systemic findings in a population of children with optic nerve hypoplasia (ONH) and to evaluate the relationship between ocular signs and neurologic findings. Method: A retrospective chart review of 53 patients with the diagnosis of ONH seen between December 1998 and September 2012 was performed. All neurodevelopmental anomalies, neuroradiologic findings, endocrinologic and systemic findings were recorded. Poor vision was defined as the visual acuity poorer than logMAR 1.0 or inadequate central steady maintained fixation. Results: Thirty (56.6%) of the 53 children with ONH were boys. Mean age at presentation was 56.2±46.8 months (range; 3 months to 18 years). Poor vision defined for the purpose of this study was found in 47.2% of 53 patients. Thirty-three (62.3%) children had nystagmus. Thirty-four (64.2%) children had strabismus. Thirteen (38.2%) of those with strabismus had esotropia, 20 (58.8%) had exotropia. The total number of the children with neurodevelopmental deficit was 22 (41.5%) in our study. Conclusion: The vision of young children with ONH should be monitored at least annually, and any refractive errors should be treated. Neuroimaging of the brain and endocrinologic evaluation is necessary in all cases with ONH.

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