Search results for "Neural"
showing 10 items of 2783 documents
Identity, origin, and migration of peripheral glial cells in the Drosophila embryo.
2008
Glial cells are crucial for the proper development and function of the nervous system. In the Drosophila embryo, the glial cells of the peripheral nervous system are generated both by central neuroblasts and sensory organ precursors. Most peripheral glial cells need to migrate along axonal projections of motor and sensory neurons to reach their final positions in the periphery. Here we studied the spatial and temporal pattern, the identity, the migration, and the origin of all peripheral glial cells in the truncal segments of wildtype embryos. The establishment of individual identities among these cells is reflected by the expression of a combinatorial code of molecular markers. This allows…
Plexin-B1 and Semaphorin 4D Cooperate to Promote Perineural Invasion in a RhoA/ROK-Dependent Manner
2012
Perineural invasion (PNI) is a tropism of tumor cells for nerve bundles located in the surrounding stroma. It is a pathological feature observed in certain tumors, referred to as neurotropic malignancies, that severely limits the ability to establish local control of disease and results in pain, recurrent growth, and distant metastases. Despite the importance of PNI as a prognostic indicator, its biological mechanisms are poorly understood. The semaphorins and their receptors, the plexins, compose a family of proteins originally shown to be important in nerve cell adhesion, axon migration, and proper central nervous system development. Emerging evidence has demonstrated that these factors a…
Induction of Neuronal Differentiation in Neurosphere Stem Cells by Ellagic Acid Derivatives
2009
A bioassay-guided fractionation of methanol extracts of stem barks, combined with screening based on Epidermal Growth Factor (EGF)-responsive neural stem cells (erNSCs) differentiation assay, has been used. This study resulted in the isolation of 3,3′-di- O-methylellagic acid 1, 3,3′-di- O-methyl ellagic acid-4- O-β-D-xylopyranoside 2, ellagic acid 3, and arjunolic acid 4. Among them, compounds 1 and 2 exhibit potent induction of neuronal differentiation in neurosphere stem cells with no cytotoxic effect. These results indicate that compounds 1 and 2 may be useful as pharmacological agents for the treatment of neurodegenerative diseases. These compounds may account, for the use of T. super…
Characterization of molecular mechanisms underlying the axonal Charcot–Marie–Tooth neuropathy caused by MORC2 mutations
2019
Mutations in MORC2 lead to an axonal form of Charcot-Marie-Tooth (CMT) neuropathy type 2Z. To date, 31 families have been described with mutations in MORC2, indicating that this gene is frequently involved in axonal CMT cases. While the genetic data clearly establish the causative role of MORC2 in CMT2Z, the impact of its mutations on neuronal biology and their phenotypic consequences in patients remains to be clarified. We show that the full-length form of MORC2 is highly expressed in both embryonic and adult human neural tissues and that Morc2 expression is dynamically regulated in both the developing and the maturing murine nervous system. To determine the effect of the most common MORC2…
A new culturing strategy optimises Drosophila primary cell cultures for structural and functional analyses
2004
Abstract Neurons in primary cell cultures provide important experimental possibilities complementing or substituting those in the nervous system. However, Drosophila primary cell cultures have unfortunate limitations: they lack either a range of naturally occurring cell types, or of mature physiological properties. Here, we demonstrate a strategy which supports both aspects integrated in one culture: Initial culturing in conventional serum-supplemented Schneider's medium (SM 20K ) guarantees acquisition of all properties known from 30 years of work on cell type-specific differentiation in this medium. Through subsequent shift to newly developed active Schneider's medium (SM active ), neuron…
Segment-specific requirements for dorsoventral patterning genes during early brain development in Drosophila.
2006
An initial step in the development of the Drosophila central nervous system is the delamination of a stereotype population of neural stem cells (neuroblasts, NBs) from the neuroectoderm. Expression of the columnar genes ventral nervous system defective (vnd), intermediate neuroblasts defective (ind) and muscle segment homeobox (msh) subdivides the truncal neuroectoderm(primordium of the ventral nerve cord) into a ventral, intermediate and dorsal longitudinal domain, and has been shown to play a key role in the formation and/or specification of corresponding NBs. In the procephalic neuroectoderm(pNE, primordium of the brain), expression of columnar genes is highly complex and dynamic, and th…
Genetic Models of the Endocannabinoid System
2009
The endocannabinoid (ECB) system comprises cannabinoid receptors, ECBs and the whole machinery for the synthesis and degradation of ECBs. It has emerged as an important signalling system in the nervous system, controlling numerous physiological processes, including synaptic transmission, learning and memory, reward, feeding, neuroprotection, neuroinflammation, and neural development. This system is also implicated in various diseases of the nervous system, and thus has become a promising therapeutic target. The use of genetically modified mice has contributed crucially to our rapidly expanding knowledge of the ECB system. In this chapter, the existing mouse mutants targeting the ECB system …
Emerging Therapeutic Strategies for Traumatic Spinal Cord Injury
2020
Spinal cord injury (SCI) is a debilitating neurologic condition with tremendous socioeconomic impact on affected individuals and the health care system. The treatment of SCI principally includes surgical treatment and marginal pharmacologic and rehabilitation therapies targeting secondary events with minor clinical improvements. This unsuccessful result mainly reflects the complexity of SCI pathophysiology and the diverse biochemical and physiologic changes that occur in the injured spinal cord. Once the nervous system is injured, cascades of cellular and molecular events are triggered at varying times. Although the cascade of tissue reactions and cell injury develops over a period of days …
A Concurrent Neural Classifier for HTML Documents Retrieval
2003
A neural based multi-agent system for automatic HTML pages retrieval is presented. The system is based on the EαNet architecture, a neural network having good generalization capabilities and able to learn the activation function of its hidden units. The starting hypothesis is that the HTML pages are stored in networked repositories. The system goal is to retrieve documents satisfying a user query and belonging to a given class (i.e. documents containing the word “football” and talking about “Sports”). The system is composed by three interacting agents: the EαNet Neural Classifier Mobile Agent, the Query Agent, and the Locator Agent. The whole system was successfully implemented exploiting t…
Massive Lesions Classification using Features based on Morphological Lesion Differences
2007
Purpose of this work is the development of an automatic classification system which could be useful for radiologists in the investigation of breast cancer. The software has been designed in the framework of the MAGIC-5 collaboration. In the automatic classification system the suspicious regions with high probability to include a lesion are extracted from the image as regions of interest (ROIs). Each ROI is characterized by some features based on morphological lesion differences. Some classifiers as a Feed Forward Neural Network, a K-Nearest Neighbours and a Support Vector Machine are used to distinguish the pathological records from the healthy ones. The results obtained in terms of sensiti…