Neuroscience
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Noisy galvanic vestibular stimulation (nGVS) has been shown to improve vestibular perception in healthy subjects. However, it is unclear whether both the semicircular canals (SCCs) and otolith organs contribute to this enhancement or is it confined to one of these structures. To elucidate this matter, nGVS amplitudes with optimal effect on postural control were determined in 12 healthy subjects during upright stance. ⋯ In addition, elevated baseline thresholds during the inter-aural translation task significantly correlated with a larger magnitude of improvement (R = 0.72, p = 0.01). In conclusion, nGVS appears to primarily impact otolith-mediated perception while only mildly affecting the SCCs. Thus, this stimulation approach could be a complementary candidate to vestibular implants that are currently limited to SCC-mediated vestibular function.
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The ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) enzymes are secreted, multi-domain matrix-associated zinc metalloendopeptidases that modify extracellular matrix components and play crucial roles in development and numerous diseases. ADAMTS18 is a member of the ADAMTS family, and genome-wide association studies made an initial association of ADAMTS18 with white matter integrity in healthy people of 72-74 years old. However, the potential roles of ADAMTS18 in central nervous system remain unclear. ⋯ Behavioral tests showed that Adamts18 KO mice had reduced levels of depression-like behaviors compared to their wild-type (WT) littermates. The increased neurite formation could be attributed in part to reduced phosphorylation levels of the collapsin response mediator protein-2 (CRMP2) due to activation of the laminin/PI3K/AKT/GSK-3β signaling pathway. Our findings revealed a critical role of ADAMTS18 in neuronal morphogenesis and emotional control in mice.
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Review
From Early to Late Neurogenesis: Neural Progenitors and the Glial Niche from a Fly's Point of View.
Drosophila melanogaster is an important model organism used to study the brain development of organisms ranging from insects to mammals. The central nervous system in fruit flies is formed primarily in two waves of neurogenesis, one of which occurs in the embryo and one of which occurs during larval stages. In order to understand neurogenesis, it is important to research the behavior of progenitor cells that give rise to the neural networks which make up the adult nervous system. ⋯ Recent discoveries in progenitors and niche cells have led to new understandings of how the developing brain shapes its diverse regions. In this review, we attempt to summarize the distinct neural progenitors and glia in the Drosophila melanogaster central nervous system, from embryo to late larval stages, and make note of homologous features in mammals. We also outline the recent advances in this field in order to define the impact that glial cells have on progenitor cell niches, and we finally emphasize the importance of communication between glia and progenitor cells for proper brain formation.
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Astrocytes, the main non-neuronal cells in the brain, have significant roles in the maintenance and survival of neurons. Oxidative stress has been implicated in various neurodegenerative disorders such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Myxobacteria produce a wide range of bioactive metabolites with notable structures and modes of action, which introduce them as potent natural product producers. ⋯ The overall results showed myxobacterial extracts, especially from the strains Archangium sp. UTMC 4070 and Cystobacter sp. UTMC 4073, were able to protect human primary astrocytes from oxidative stress.
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Parkinson's disease (PD) is a common neurodegenerative disease that is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc). The proapoptotic BH3-only protein Bim has been reported to be involved in dopaminergic neurodegeneration of experimental PD. However, an in situ expression profile of Bim in PD has not been performed, and the cell types of which Bim accounts for PD pathogenesis is unclear. ⋯ Bim△Dat mice are shown to be resistant to MPTP-induced neurotoxicity, confirming that the induction of Bim in dopaminergic neurons is responsible for parkinsonian neurodegeneration. Furthermore, we demonstrated with dopaminergic neuron-specific c-Jun knockout (c-Jun△Dat) that the transcriptional upregulation of Bim of nigral dopaminergic neurons was c-Jun-dependent and further validated the detrimental role of c-Jun in dopaminergic neurodegeneration. Together, these data specify that c-Jun-mediated Bim upregulation in nigral dopaminergic neurons contributes to parkinsonian neurodegeneration.