Mechanisms of Neuronal Migration during Corticogenesis

Mechanisms of Neuronal Migration during Corticogenesis PDF Author: Chiaki Ohtaka-Maruyama
Publisher: Frontiers Media SA
ISBN: 2889198863
Category : Neurosciences. Biological psychiatry. Neuropsychiatry
Languages : en
Pages : 185

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Book Description
The cerebral cortex plays central roles in many higher-order functions such as cognition, language, consciousness, and the control of voluntary behavior. These processes are performed by the densely interconnected networks of excitatory pyramidal neurons and inhibitory interneurons, and the balanced development of these two types of neuron is quite important. During cortical development, pyramidal neurons and interneurons show quite different migratory behaviors: radial migration and tangential migration, respectively. Pyramidal neurons are generated in the ventricular zone of the dorsal telencephalon, and migrate radially along radial glial fibers toward the pial surface, forming a six-layered cortical structure in an “ inside-out” manner. On the other hand, cortical interneurons are generated in the medial and caudal ganglionic eminence in the ventral telencephalon, and follow long tangential migratory paths into the cortex. Defects in these migration processes result in abnormalities in the cortical layer structure and neuronal networks, which may cause various neurological and psychiatric conditions such as epilepsy and schizophrenia. Accordingly, besides basic scientific interest, elucidation of the mechanism of neuronal migration is essential for understanding the pathogenesis of these diseases. This Research Topic includes a series of articles ranging from the basic mechanism of neocortical development to the malformation and evolution of the neocortex. We do hope that the present ebook will further stimulate the interest in the fascinating investigations of neuronal migration and corticogenesis.

Mechanisms of Neuronal Migration during Corticogenesis

Mechanisms of Neuronal Migration during Corticogenesis PDF Author: Chiaki Ohtaka-Maruyama
Publisher: Frontiers Media SA
ISBN: 2889198863
Category : Neurosciences. Biological psychiatry. Neuropsychiatry
Languages : en
Pages : 185

Get Book Here

Book Description
The cerebral cortex plays central roles in many higher-order functions such as cognition, language, consciousness, and the control of voluntary behavior. These processes are performed by the densely interconnected networks of excitatory pyramidal neurons and inhibitory interneurons, and the balanced development of these two types of neuron is quite important. During cortical development, pyramidal neurons and interneurons show quite different migratory behaviors: radial migration and tangential migration, respectively. Pyramidal neurons are generated in the ventricular zone of the dorsal telencephalon, and migrate radially along radial glial fibers toward the pial surface, forming a six-layered cortical structure in an “ inside-out” manner. On the other hand, cortical interneurons are generated in the medial and caudal ganglionic eminence in the ventral telencephalon, and follow long tangential migratory paths into the cortex. Defects in these migration processes result in abnormalities in the cortical layer structure and neuronal networks, which may cause various neurological and psychiatric conditions such as epilepsy and schizophrenia. Accordingly, besides basic scientific interest, elucidation of the mechanism of neuronal migration is essential for understanding the pathogenesis of these diseases. This Research Topic includes a series of articles ranging from the basic mechanism of neocortical development to the malformation and evolution of the neocortex. We do hope that the present ebook will further stimulate the interest in the fascinating investigations of neuronal migration and corticogenesis.

Mechanisms of Neuronal Migration During Corticogenesis

Mechanisms of Neuronal Migration During Corticogenesis PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The cerebral cortex plays central roles in many higher-order functions such as cognition, language, consciousness, and the control of voluntary behavior. These processes are performed by the densely interconnected networks of excitatory pyramidal neurons and inhibitory interneurons, and the balanced development of these two types of neuron is quite important. During cortical development, pyramidal neurons and interneurons show quite different migratory behaviors: radial migration and tangential migration, respectively. Pyramidal neurons are generated in the ventricular zone of the dorsal telencephalon, and migrate radially along radial glial fibers toward the pial surface, forming a six-layered cortical structure in an " inside-out" manner. On the other hand, cortical interneurons are generated in the medial and caudal ganglionic eminence in the ventral telencephalon, and follow long tangential migratory paths into the cortex. Defects in these migration processes result in abnormalities in the cortical layer structure and neuronal networks, which may cause various neurological and psychiatric conditions such as epilepsy and schizophrenia. Accordingly, besides basic scientific interest, elucidation of the mechanism of neuronal migration is essential for understanding the pathogenesis of these diseases. This Research Topic includes a series of articles ranging from the basic mechanism of neocortical development to the malformation and evolution of the neocortex. We do hope that the present ebook will further stimulate the interest in the fascinating investigations of neuronal migration and corticogenesis.

The Extracellular Environment in Controlling Neuronal Migration During Neocortical Development

The Extracellular Environment in Controlling Neuronal Migration During Neocortical Development PDF Author: Yuki Hirota
Publisher: Frontiers Media SA
ISBN: 2889669300
Category : Science
Languages : en
Pages : 217

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Book Description


The Role of Endocytosis in Neuronal Migration

The Role of Endocytosis in Neuronal Migration PDF Author: Jennifer Cynthia Shieh
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 200

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Book Description
Disruptions in neuronal migration have been implicated in a variety of human mental disorders, including epilepsy, autism, and schizophrenia. Despite the critical role of migration during nervous system development, the basic physical and cytoskeletal mechanisms of coordinated neuronal movement have not yet been fully characterized. A migrating neuron moves with morphologically distinct steps: a single leading process extends ahead of a stationary cell soma, followed by the formation of a cytoplasmic dilation ahead of the nucleus, subsequent movement of the nucleus into the dilation, and retraction of the cell rear. The temporal and spatial regulation of adhesion is important for the proper progression of these steps. I investigated the role of endocytosis in regulating adhesion during neuronal migration. Using genetic and pharmacological methods to disrupt endocytosis either in vitro or in vivo leads to altered neuronal migration. Introducing dominant negative clathrin or dynamin into the developing cortex delays radial migration in vivo. Pharmacologically inhibiting clathrin or dynamin reduces the velocity of anterior subventricular zone (SVZa) neurons migrating in a three-dimensional matrix in vitro. Components of clathrin endocytic machinery are localized to the dilation region of a migrating neuron at points of matrix attachment. The absence of adhesion molecules at the cell rear led us to the hypothesis that endocytosis weakens adhesions in the dilation to allow the cell rear to move forward during migration. In support of this hypothesis, exposing SVZa explants to pharmacological inhibitors of either clathrin or dynamin prevents migration out of explants, and neurons that have migrated out have altered morphology and adhesion molecule distribution. Neurons exposed to a dynamin inhibitor tend to have "tails" of membrane at the rear, and these tails contain adhesion molecules. The presence of adhesion molecules at the rear of migrating neurons exposed to a dynamin inhibitor supports the idea that endocytosis plays a role in regulating adhesion disassembly. Endocytosis likely plays a critical role in general neuronal migration regardless of the specific neuronal subtype, migration mode, or substrate.

Mechanisms Governing Neuronal Migration and Morphology

Mechanisms Governing Neuronal Migration and Morphology PDF Author: Margareta Nikolić
Publisher: S. Karger AG (Switzerland)
ISBN: 9783805584654
Category : Cell migration
Languages : en
Pages : 0

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Book Description
The correct migration of neurons to specific targets underlies the normal formation and function of our nervous system. Defective movement of neurons results in their aberrant function or death, thus causing a range of developmental problems. Neurons move by responding to extracellular cues which alter the dynamic organization of cytoskeletal elements via complex and often overlapping signaling pathways. Changes in external cues or intracellular signaling molecules are responsible for altered neuronal movement and behavior, and are increasingly being associated with the occurrence of lissencephaly, epilepsy and mental retardation. This issue provides current findings and future directions towards understanding how the dynamic organization of the neuronal cytoskeleton affects movement and the consequences of normal and altered neuronal migration on the nervous system. The topics highlight the importance of specific proteins that regulate actin filaments and microtubules, and how their changes affect neuronal translocation. The effects of genetic or environmental alterations on the formation of the nervous system and the power of high-resolution imaging in analyzing both normal and defective development are emphasized. The volume will thus be of interest to a wide range of molecular and cellular neurobiologists, developmental biologists and neurologists.

Mouse Brain Development

Mouse Brain Development PDF Author: Andre M. Goffinet
Publisher: Springer Science & Business Media
ISBN: 3540480021
Category : Science
Languages : en
Pages : 347

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Book Description
Our understanding of the molecular mechanisms involved in mammalian brain development remains limited. However, the last few years have wit nessed a quantum leap in our knowledge, due to technological improve ments, particularly in molecular genetics. Despite this progress, the available body of data remains mostly phenomenological and reveals very little about the grammar that organizes the molecular dictionary to articulate a pheno type. Nevertheless, the recent progress in genetics will allow us to contem plate, for the first time, the integration of observation into a coherent view of brain development. Clearly, this may be a major challenge for the next century, and arguably is the most important task of contemporary develop mental biology. The purpose of the present book is to provide an overview that syn thesizes up-to-date information on selected aspects of mouse brain devel opment. Given the format, it was not possible to cover all aspects of brain development, and many important subjects are missing. The selected themes are, to a certain extent, subjective and reflect the interests of the contributing authors. Examples of major themes that are not covered are peripheral nervous system development, including myelination, the development of the hippocampus and several other CNS structures, as well as the developmental function of some important morphoregulatory molecules.

Tracking Neuronal Development in the Adult Brain

Tracking Neuronal Development in the Adult Brain PDF Author: Karen Bakhshetyan
Publisher:
ISBN:
Category :
Languages : en
Pages : 202

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Book Description
The knowledge about molecular and cellular pathways orchestrating neuronal development in the adult brain can be used to build up efficient strategies for cell replacement therapies. Adult neurogenesis is a very dynamic process, and it is crucial to monitor it directly to decipher mechanisms required for neuronal development. Furthermore, it is important to develop label-free imaging methods. My work is, in part, aimed at addressing these challenges. Adult-born neurons migrate densely along blood vessels and glial tubes in the rostral migratory stream (RMS). This alignment may create anisotropy which can be detected in polarized light. I first tried this technique for label-free detection of migratory cells in the RMS. While this imaging may have some promises, it showed that anisotropy in migrating cells is quite low and its detection is hampered by large signals deriving from nearby myelinated axons. I further studied the migration of virally labeled neuroblasts to elucidate some of the mechanisms required for their migration. GABAergic signaling plays an important role in neuronal migration and is defined by transmembrane Cl- gradient. This, in turn is controlled by the Cl- extruding co-transporter KCC2, known to have a late developmental expression. The role of KCC2 in neuronal migration is unknown and my experiments suggest that this co-transporter is involved in the radial, but not tangential migration of neuroblasts. Finally, I explored in vivo the odor-related structural plasticity of adult-born neurons in the olfactory bulb (OB). It remains unknown how OB functioning is adjusted to rapidly changing odor environment when new synapses of adult-born neurons have not yet been formed. My in vivo two-photon imaging data complements the previous work in our lab, revealing altogether a new form of structural plasticity in the adult OB. Thus, using diverse imaging methods I tried to better understand the migration and plasticity of new neurons in the adult brain.

Normal and Abnormal Development of the Cortex

Normal and Abnormal Development of the Cortex PDF Author: Albert M. Galaburda
Publisher: Springer
ISBN:
Category : Medical
Languages : en
Pages : 224

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Book Description
This is an examination of the normal and abnormal development of cortex. Issues covered include the nature and nurture of cortical development, mechanisms of neuronal migration, intra- and extra-cellular control of neuronal migration and genetic insights into cerebral cortical development.

Coordination of Neuronal Proliferation and Migration During Corticogenesis

Coordination of Neuronal Proliferation and Migration During Corticogenesis PDF Author: Élodie Gautier
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Cortical cytoarchitecture relies on the spatiotemporal coordination of neuronal production rate, precursors cell-cycle control and neuronal radial migration towards the cortical plate. In the primate, area 17 supragranular layers are more developed than in area 18, due to higher proliferation and neuronal production rates in area 17 between E77-80. Two-photon videomicroscopy observations on cortical organotypic slices revealed that radial migration is faster in area 17 than 18. This indicates that area-specific variations of proliferation and migration rates are congruent during corticogenesis. The study of molecular mechanisms underlying the coordinated regulation of proliferation and migration focused on the cell-cycle regulator p27kip1, which promotes migration, via inhibition of the Rhoa GTPase by its C-terminal domain. This p27 dual function could play a major role during the Interkinetic Nuclear Migration (INM) performed by cortical precursor cells from the ventricular zone, in synchrony with the cell-cycle phases. Mutant forms of p27 or shRNA were electroporated into neuroblasts of E14-15 mice embryos. Two-photon videomicroscopy observations on organotypic slices revealed that p27 affects INM, promotes differentiative divisions and neuronal radial migration, though its C-terminal domain. P27 is thus part of a molecular network which finely tunes, in an area-specific manner, the successive rounds of divisions of precursor, as well as the migratory behavior of the newborn neurons.

The Reeler Mouse as a Model of Brain Development

The Reeler Mouse as a Model of Brain Development PDF Author: Catherine Lambert de Rouvroit
Publisher: Springer Science & Business Media
ISBN: 3642722571
Category : Medical
Languages : en
Pages : 117

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Book Description
Only five years ago, nobody in his right mind would have consid ered publishing a book on reeler as a model for brain develop ment. Although this interesting mutation has been with us for half a century, it is fair to say that, in spite of a wave of enthusiasm in the late sixties and early seventies, generated primarily by Sidman, Caviness and colleagues, studies of reeler mice fell pro gressively out of fashion during the next two decades. All that changed almost overnight when the cloning of the reeler gene, dubbed reelin, was reported in Tom Curran's laboratory in 1995. The fact that the same gene was identified at the same time independently by two other groups using positional cloning sug gested strongly that reelin was the right candidate. Although the key experiments of transgenic rescue have not been made (and perhaps will never be), the equation "reeler is reelin" has been established beyond reasonable doubt, as alterations of the reelin gene and/or its expression have been found in at least five alleles of reeler and in the mutation Shaking Rat Kawasaki (SRK), an ortholog of reeler.