This book systematically discusses the pathogenesis, prevention, and the current and potential clinical treatment of hearing loss, as well as the latest advances in hearing research. Hearing loss is a prevalent sensory disorder, which according to a 2015 World Health Organization (WHO) report affected 9% of the global population in 2015. As populations continue to age, more and more people are suffering from the condition, with 60% of those aged between 65 and 75 affected. Hearing loss seriously affects patients’ ability to work ability and quality of life, and as such deafness has become an increasingly urgent social problem around the globe. Sensorineural hearing loss is mainly caused by damage to the hair cells (HCs), and the subsequent loss of spiral ganglion neurons (SGNs). Damage to the HCs in the inner ear can result from exposure to loud noises and environmental and chemical toxins as well as genetic disorders, aging, and certain medications. This book provides ENT specialists and researchers, as well as individuals affected a comprehensive introduction to the field of hearing loss.

Sensory hair cells are the specialized mechanosensory receptors found in vertebrate auditory, vestibular, and lateral line organs that transduce vibratory and acoustic stimuli into the sensations of hearing and balance. Hair cells can be damaged due to such factors as aging, ototoxic chemicals, acoustic trauma, infection, or genetic factors. Loss of these hair cells lead to deficits in hearing and balance, and in mammals, such deficits are permanent. In contrast, non-mammalian vertebrates exhibit the capability to regenerate missing hair cells. Researchers have been examining the process of hair cell death and regeneration in animal models in an attempt to find ways of either preventing hair cell loss or stimulating the production of new hair cells in mammals, with the ultimate goal of finding new therapeutics for human sensorineural hearing and balance deficits. This has led to a wide array of research on sensory hair cells- such as understanding the factors that cause hair cell loss and finding agents that protect them from damage, elucidating the cell signaling pathways activated during hair cell death, examining the genes and cellular pathways that are regulated during the process of hair cell death and regeneration, and characterizing the functional sensory loss and recovery following acoustic or ototoxic insults to the inner ear. This research has involved cell and developmental biologists, physiologists, geneticists, bioinformaticians, and otolaryngologists. In this Research Topic, we have collated reviews of the past progress of hair cell death and regeneration studies and original research articles advancing sensory hair cell death and regeneration research into the future.

Now in two volumes, this completely updated and expanded edition of Embryonic Stem Cells: Methods and Protocols provides a diverse collection of readily reproducible cellular and molecular protocols for the manipulation of nonhuman embryonic stem cells. Volume one, Embryonic Stem Cell Protocols: Isolation and Characterization, Second Edition, provides a diverse collection of readily reproducible cellular and molecular protocols for the isolation, maintenance, and characterization of embryonic stem cells. The second volume, Embryonic Stem Cell Protocols: Differentiation Models, Second Edition, covers state-of-the-art methods for deriving many types of differentiating cells from ES cells. Together, the two volumes illuminate for both novices and experts our current understanding of the biology of embryonic stem cells and their utility in normal tissue homeostasis and regenerative medicine applications.

Hearing loss is the most common form of sensory impairment in humans, affecting 360 million persons worldwide. In parallel, tinnitus disorder, the perception of a phantom sound often described as a ringing or buzzing, affects around 10–15% of the general population and interferes with daily life. Hyperacusis, defined as a hypersensitivity to moderate-intensity sounds often co-occurs with tinnitus suggesting a common mechanism of dysfunction for these two perceptual disorders. Whereas some drug candidates are in the process of being developed, nowadays no effective treatment exists to cure hearing loss and tinnitus. The topic of this book was selected with the goal of emphasizing mechanisms that induce hearing loss and tinnitus which lead the selection of promising targets for hearing disorder treatment. Hair cells (HC) are the sensory cells of the inner ear required for both auditory and vestibular functions in all vertebrates. HC are progressively lost during ageing and they are in addition sensitive to physical and acoustic traumas, infectious diseases and chemicals present in commonly used treatments such as anticancer, antimalarial or antibiotics. As adult mammals--including humans--cannot regenerate dead HC, all the possible injury could result in irreversible and permanent hearing loss. It has been shown, however, that a limited capacity to regenerate HC exists in mouse at an early stage of development. The regenerative capacity of HC then appears simply “repressed” in adult mammals, and one could expect it will be possible to re-activate it with an appropriate therapeutic approach which is still to be defined. Immune-mediated inner ear disease has been introduced and accepted as one SNHL pathophysiology; it responds to immunosuppressive therapy and is one of the few reversible forms of bilateral SNHL. Macrophages are always present in the spiral ligament of the lateral wall and are activated in response to various types of stimuli, including noise exposure, ischemia, mitochondrial damage, and surgical stress. Recent studies have also revealed another type of immune cell, called perivascular melanocyte-like macrophages (PVM/Ms), in the stria vascularis. The book will include a review of inflammatory/immune cells in the cochlear lateral wall, the pathways involved in cochlear damage and their potential as therapeutic targets. The final chapter provides an overview of current animal model of tinnitus and hyperacusis. Nowadays no effective treatment exists to cure tinnitus and hyperacusis. One major obstacle to arises from the fact that tinnitus is a subjective phenomenon, the only possible diagnosis relies on self-reports of the subjects. The main constraint of the use of animal models is the subjective character of tinnitus. This chapter describe the advancement in animal models which play an important role in revealing the underlying mechanisms and treatment for tinnitus and hyperacusis.

Recent scientific breakthroughs, celebrity patient advocates, and conflicting religious beliefs have come together to bring the state of stem cell researchâ€"specifically embryonic stem cell researchâ€"into the political crosshairs. President Bush's watershed policy statement allows federal funding for embryonic stem cell research but only on a limited number of stem cell lines. Millions of Americans could be affected by the continuing political debate among policymakers and the public. Stem Cells and the Future of Regenerative Medicine provides a deeper exploration of the biological, ethical, and funding questions prompted by the therapeutic potential of undifferentiated human cells. In terms accessible to lay readers, the book summarizes what we know about adult and embryonic stem cells and discusses how to go about the transition from mouse studies to research that has therapeutic implications for people. Perhaps most important, Stem Cells and the Future of Regenerative Medicine also provides an overview of the moral and ethical problems that arise from the use of embryonic stem cells. This timely book compares the impact of public and private research funding and discusses approaches to appropriate research oversight. Based on the insights of leading scientists, ethicists, and other authorities, the book offers authoritative recommendations regarding the use of existing stem cell lines versus new lines in research, the important role of the federal government in this field of research, and other fundamental issues.

The brain is the most complex organ in our body. Indeed, it is perhaps the most complex structure we have ever encountered in nature. Both structurally and functionally, there are many peculiarities that differentiate the brain from all other organs. The brain is our connection to the world around us and by governing nervous system and higher function, any disturbance induces severe neurological and psychiatric disorders that can have a devastating effect on quality of life. Our understanding of the physiology and biochemistry of the brain has improved dramatically in the last two decades. In particular, the critical role of cations, including magnesium, has become evident, even if incompletely understood at a mechanistic level. The exact role and regulation of magnesium, in particular, remains elusive, largely because intracellular levels are so difficult to routinely quantify. Nonetheless, the importance of magnesium to normal central nervous system activity is self-evident given the complicated homeostatic mechanisms that maintain the concentration of this cation within strict limits essential for normal physiology and metabolism. There is also considerable accumulating evidence to suggest alterations to some brain functions in both normal and pathological conditions may be linked to alterations in local magnesium concentration. This book, containing chapters written by some of the foremost experts in the field of magnesium research, brings together the latest in experimental and clinical magnesium research as it relates to the central nervous system. It offers a complete and updated view of magnesiums involvement in central nervous system function and in so doing, brings together two main pillars of contemporary neuroscience research, namely providing an explanation for the molecular mechanisms involved in brain function, and emphasizing the connections between the molecular changes and behavior. It is the untiring efforts of those magnesium researchers who have dedicated their lives to unraveling the mysteries of magnesiums role in biological systems that has inspired the collation of this volume of work.

Immunological Tolerance: Methods and Protocols is a comprehensive guide to the techniques currently used for culturing and characterising the cell types responsible for imposing self-tolerance and the experimental models employed to study their function both in vitro and in vivo. This guide is aimed at AIDS researchers, immunologists, transplant surgeons/specialists, and biotechnologists.

Volume 1: The Ear (edited by Paul Fuchs) Volume 2: The Auditory Brain (edited by Alan Palmer and Adrian Rees) Volume 3: Hearing (edited by Chris Plack) Auditory science is one of the fastest growing areas of biomedical research. There are now around 10,000 researchers in auditory science, and ten times that number working in allied professions. This growth is attributable to several major developments: Research on the inner ear has shown that elaborate systems of mechanical, transduction and neural processes serve to improve sensitivity, sharpen frequency tuning, and modulate response of the ear to sound. Most recently, the molecular machinery underlying these phenomena has been explored and described in detail. The development, maintenance, and repair of the ear are also subjects of contemporary interest at the molecular level, as is the genetics of hearing disorders due to cochlear malfunctions.

This book reviews recent progress in understanding of the signaling and biochemistry of GM3 ganglioside in eukaryotic cells. GM3 is the simplest of the gangliosides and the precursor of other gangliosides. It is expressed in the outer leaflet of plasma cell membranes and has roles in the recognition, interaction, binding, adhesion, and motility of cells. In addition, GM3 has been documented to have functional roles in cell migration, proliferation, senescence, and apoptosis. The full range of topics of interest are addressed in the book. The early chapters discuss the synthesis of GM3, its molecular localization in cells, and its basic function as an interacting molecule. The ways in which GM3 exerts its effects via various growth factor receptors are fully explored. Current knowledge of the part played by GM3 in health and disease is discussed in depth. For example, its roles in preventing inflammation, inhibiting tumor angiogenesis and tumor growth, and suppressing arthritis are highlighted, and attention drawn to the significance of GM3 as a driver of impaired wound healing in diabetics. The book will be of interest to all who want a comprehensive update on research in this field.