Role Of Glial Cells Of The Central And Peripheral Nervous System In The Pathogenesis Of Neurodegenerative Disorders

Immune responses within the brain are still scarcely explored. Nerve tissue damage is accompanied by the activation of glial cells, primarily microglia and astroglia, and such activation is responsible for the release of cytokines and chemokines that maintain the local inflammatory response and actively recruit lymphocytes and monocytes to the damaged areas. Theoretically, these responses are designed to repair the brain damage. However, alterations, or a chronic perpetuation of these responses may underlie a number of neuro-pathologies. It is thought that each inflammatory scenario within the brain have a specific biochemical footprint characterized by the release of determined cytokines, chemokines and growing factors able to define particular immunological responses. Alongside, glial cells transform their cell body, become larger and develop higher number of branches adopting an active morphological phenotype. These changes are related with the search of interactions with other cells, such as bystander resident cells of the brain parenchyma, but also cells homing from the blood stream. In this process, microglia and astrocytes communicates with other cells by the formation of specific intercellular connections that are still poorly understood. These interactions are complex and entail the arrangement of cytoskeletal compounds, secretory and phagocytic domains. In this particular crosstalk there is a two-way communication in which glial cells and target cells come together establishing interfaces with specific information exchange. This way, glial cells orchestrate the particular response recruiting cellular subsets within the central nervous system and organizing the resolution of the brain damage. In this Frontiers Research Topic, we compile a selection of articles unfolding diverse aspects of glial-derived inflammation, focused on neurodegenerative diseases and other nervous system disorders, with special emphasis on microglia/macrophages as leading actors managing neuro-immunity.

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. ​

Thirty-five years ago, when Stephen Kuffler and his colleagues at Harvard initiated a new era of research on the properties and functions of neuroglial cells, very few neuro scientists were impressed at the time with the hypothesis that neuroglial cells could have another, though more subtle, role to play in the nervous system than to provide static support to neurons. Today, very few neuroscientists are unaware of the fact that multiple interactions between neurons and glial cells have been described, and that they consti tute the basis for understanding the function and the pathology of the nervous system. Glial cells outnumber neurons and make up about one-half of the bulk of the nervous system. They are divided into two major classes: first, the macroglia, which include astrocytes and oligodendrocytes in the central nervous system, and the Schwann cells in the peripheral nervous system; and second, the microglial cells. These different classes of glial cells have different functions and contribute in different ways in the devel opment, function, and the pathology of the nervous system.

Accumulation on glia is an active pathological element in many neurological disorders. Gliosis produces neuroinflammation through both neurotrophic and inflammatory means, but the exact mechanism through which this happens remain unclear. It is suspected that damage to neurons activates the growth of glial cells. The proposed book focuses on the interaction between neurons and glia to help elucidate the pathophysiology of neuroinflammation in neurological disorders.​

The majority of cells in the nervous system are glial cells. During de velopment, these cells provide growth factors that stimulate the proli feration, migration and survival of neurones and their precursors, and promote and guide axonal growth. In the mature nervous system, glial cells provide insulating myelin sheath around axons and provide metabo lic and structural support for neurones. Glial cells also have a major influence on the local response to injury of central nerve tracts and the peripheral nervous system, either promoting, or inhibiting, axona l regrowth and recovery of lost function. This book provides a compreh ensive, state-of-the-art overview of research into the development, fu nction and malfunction of glial cells. It offers a compelling insight into how basic research throws light onto diseases and disorders and p oints the way towards treatments. Teams of internationally renowned ex perts, all active in research, have contributed chapters.

A timely overview covering the three major types of glial cells in the central nervous system - astrocytes, microglia, and oligodendrocytes. New findings on glia biology are overturning a century of conventional thinking about how the brain operates and are expanding our knowledge about information processing in the brain. The book will present recent research findings on the role of glial cells in both healthy function and disease. It will comprehensively cover a broad spectrum of topics while remaining compact in size.