Astrocytes Cell Biology And Pathology Of Astrocytes

This volume is made up of papers presented at the Second International Altschul Symposium: Biology and Pathology of Astrocyte-Neuron Interactions. The symposium was held in Saskatoon, Canada at the University of Saskatchewn in May, 1992 in memory of Rudolf Altschul, a graduate of the University of Prague and a pioneer in the fields of the biology of the vascular and nervous systems. Dr. Altschul was Professor and Head of the Department of Anatomy at the University of Saskatchewan from 1955 to 1963. The Altschul Symposia were made possible by an endowment left by Anni Altschul and by other contributions. The symposia are held biennially. One of the greatest challenges for present day scientists is to uncover the mechanisms of brain function. Although cellular anatomy of the nervous system has already been well outlined and indeed was delineated by the beginning of the century, experimental analysis of the function of the brain is relatively recent. The framework of the brain is made up of stellate cells, the astrocytes, which are interconnected by means of their processes, thus presenting a meshwork through which the neurons send their axons, accompanied by oligodendrocytes. Microglia are distributed throughout the brain.

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A team of authors from prestigious academic schools contributed to draw up a project that would give a detailed account of astrocyte's morphology and physiology, examining thoroughly all the astrocyte's types; giving an accurate description of their morphology, location, function in the brain; and illustrating their physiology and pathology in terms of dealing with neurons through "gliotransmitters," ionic channels, and membrane receptors expression. This book gives an overview of the crucial role of astrocytes in the physiology of the CNS and in the pathogenesis of several CNS disorders suggesting that the shift from a neurocentric view to one that incorporates astrocytes in disease models for drug discovery is a critical step in renewing drug development strategies to treat neurodegenerative diseases.

Astrocytes: Cell Biology and Pathology of Astrocytes, Volume 3 deals with the involvement of astrocytes in neurological and neuropathological states of brain function. This volume discusses the expression of astrocyte-specific immunological markers and plasma membrane structures; the dynamics of the cytoskeleton and cell cycle; and the reactivity to injury and response of astrocytes in selected pathological and genetic states. The text also aims to inspire new ideas and research on astrocyte functions as well as on the pathogenesis of neurological disorders. Neuroscientists, cell biologists, clinicians, neuropathologists, and pediatric neurologists will find the book invaluable.

Astrocytes were the original neuroglia that Ramón y Cajal visualized in 1913 using a gold sublimate stain. This stain targeted intermediate filaments that we now know consist mainly of glial fibrillary acidic protein, a protein used today as an astrocytic marker. Cajal described the morphological diversity of these cells with some ast- cytes surrounding neurons, while the others are intimately associated with vasculature. We start the book by discussing the heterogeneity of astrocytes using contemporary tools and by calling into question the assumption by classical neuroscience that neurons and glia are derived from distinct pools of progenitor cells. Astrocytes have long been neglected as active participants in intercellular communication and information processing in the central nervous system, in part due to their lack of electrical excitability. The follow up chapters review the “nuts and bolts” of ast- cytic physiology; astrocytes possess a diverse assortment of ion channels, neu- transmitter receptors, and transport mechanisms that enable the astrocytes to respond to many of the same signals that act on neurons. Since astrocytes can detect chemical transmitters that are released from neurons and can release their own extracellular signals there is an increasing awareness that they play physiological roles in regulating neuronal activity and synaptic transmission. In addition to these physiological roles, it is becoming increasingly recognized that astrocytes play critical roles during pathophysiological states of the nervous system; these states include gliomas, Alexander disease, and epilepsy to mention a few.

Astrocytes, the most prevalent type of cell found in the brain, are glial cells that play a critical role in the support and maintenance of homeostatic conditions in the central nervous system (CNS). In addition to regulating synaptic function and neuronal development, astrocytes contribute to CNS immune responses and regulate permeability of the blood-brain barrier. Astrocytes respond to, and become activated by, a variety of molecular events in the CNS including the appearance of abnormal molecules, the disappearance of signaling molecules that are typically present, and changes in extracellular levels of various cytokines and chemokines. Under normal physiological conditions, astrocytic activation can be advantageous, as it can help protect the CNS from pathogens or injury; however, if this activation is sustained for a prolonged period, it can lead to detrimental astrocyte reactivity. This current book provides new developments in astrocyte research. The first chapter reviews pathological roles of astrocytes in brain edema formation. Chapter Two discusses neuroimmune interactions of astrocytes with other CNS cell types. Chapter Three focuses on astrocytes in amyotrophic lateral sclerosis. The final chapter studies astrocyte's response to stress and injury.

Proceedings of the Fourth International Altschul Symposium held at Saskatoon, Saskatchewan, Canada, June 27-29, 1996

This book reviews the role of glial cells (astrocytes, microglia, oligodendroglia, satellite cells, and Schwann cells) in neuronal health and diseases. It discusses the latest advances in understanding their origin, differentiation, and hemostasis. The book also examines the role of microglial cells in central nervous system (CNS) development, maintenance, and synaptic plasticity. Further, the book presents the functions of astrocytes in healthy CNS and their critical role in CNS disorders, including Parkinson's and Alzheimer's diseases. Notably, the book describes the pathobiology, molecular pathogenesis, stem cells, and imaging characteristics of gliomas. It defines the role of glial cells in regulating iron homeostasis and their effect on the neurodegeneration of neurons. Lastly, it covers the structure, function, and pathology of oligodendrocytes and their role in neuronal health and disease. ​