The Dentate Gyrus A Comprehensive Guide To Structure Function And Clinical Implications

The dentate gyrus is a part of the brain that has been a topic of intense interest since the beginning of neuroscience, and pioneering studies from the distant and recent past attest to this. One of the reasons for such interest is that this structure provides some of the most remarkable examples of plasticity within the nervous system. In addition, it is critical to normal cognitive function, although exactly how and when is still a question that eludes answers. Furthermore, abnormalities within the dentate gyrus appear to play a role in diverse clinical conditions, from depression to epilepsy and traumatic brain injury. The primary goal of this book is to provide a context, or background, upon which the detailed knowledge of the current era can be appreciated. A series of overviews are provided to clarify essentials related to structural organization and development, cellular components, neurotransmitters and neuromodulators, plasticity, and clinical relevance. * Covers the topic comprehensively from anatomy to cellular and systems perspectives* Includes basic research and addresses translational implications, so it will be useful to both researchers in the laboratory and clinicians who conduct experiments in humans* Chapters provide fundamentals, but also details and ample references for further review of the topic

"The dentate gyrus (DG) is one of the most sensitive regions to various brain insults due to the occurrence of neurogenesis in its subgranular zone. Thus, it may serve as a brain sensor to radiation exposure, chemical and biological toxins, alcohol abuse, smoking, drug treatments, hormone imbalances, stress, pain, hypoxia, brain trauma, malnutrition and aging. DG is also involved in the pathogenesis of multiple neurological and neuropsychological disorders including intractable temporal lobe epilepsy (TLE), Alzheimer's disease (AD), major depressive disorder (MDD), post-traumatic stress disorder (PTSD), and schizophrenia. Over decades of research, our understanding regarding the function and physiology of the DG is ever-changing. While it is commonly believed that the dentate granule cells are primarily responsible for executing higher brain functions such as learning and memory, there is increasing evidence demonstrating that the glial cells, particularly microglia, astrocytes and oligodendrocytes, are also involved in memory formation. Therefore, a book that systematically reviews DG structure, function and health implications is needed to update clinicians and researchers with state-of-the-art knowledge. In the first three chapters of this book, the recent progresses in the study of DG development with relevant molecular mechanisms, the cytoarchitectonics of DG with laminar and sublaminar distribution of different types of neurons and glial cells, as well as afferent and efferent of the DG and their neurophysiological roles will be described respectively. In Chapters 4 and 5, DG as a brain sensor to radiation exposure, and pre- and post-natal radiation-induced DG damage and cognitive impairment will be reviewed accordingly. The involvement of DG in pathogenesis of neurological disorders including TLE and AD will be discussed in Chapters 6 and 7. Finally, in the last two chapters, i.e., Chapters 8 and 9, the roles of DG in the development of neuropsychological disorders including MDD, PTSD and schizophrenia will be presented"--

The dentate gyrus (DG) is an important part of hippocampal formation and is believed to be involved in a variety of brain functions including episodic and spatial memory and the exploration of novel environments. In several neurodegenerative disorders, significant pathology occurs in the DG which may be involved in the development of clinical dementia. This book discusses the structure of the dentate gyrus as well as the role it plays in diseases and potential health implications.

The dentate gyrus (DG) is an important part of hippocampal formation and is believed to be involved in a variety of brain functions including episodic and spatial memory and the exploration of novel environments. In several neurodegenerative disorders, significant pathology occurs in the DG which may be involved in the development of clinical dementia. This book discusses the structure of the dentate gyrus as well as the role it plays in diseases and potential health implications.

The hippocampus mediates several higher brain functions, such as learning, memory, and spatial coding. The input region of the hippocampus, the dentate gyrus, plays a critical role in these processes. Several lines of evidence suggest that the dentate gyrus acts as a preprocessor of incoming information, preparing it for subsequent processing in CA3. For example, the dentate gyrus converts input from the entorhinal cortex, where cells have multiple spatial fields, into the spatially more specific place cell activity characteristic of the CA3 region. Furthermore, the dentate gyrus is involved in pattern separation, transforming relatively similar input patterns into substantially different output patterns. Finally, the dentate gyrus produces a very sparse coding scheme in which only a very small fraction of neurons are active at any one time. How are these unique functions implemented at the level of cells and synapses? Dentate gyrus granule cells receive excitatory neuron input from the entorhinal cortex and send excitatory output to the hippocampal CA3 region via the mossy fibers. Furthermore, several types of GABAergic interneurons are present in this region, providing inhibitory control over granule cell activity via feedback and feedforward inhibition. Additionally, hilar mossy cells mediate an excitatory loop, receiving powerful input from a small number of granule cells and providing highly distributed excitatory output to a large number of granule cells. Finally, the dentate gyrus is one of the few brain regions exhibiting adult neurogenesis. Thus, new neurons are generated and functionally integrated throughout life. How these specific cellular and synaptic properties contribute to higher brain functions remains unclear. One way to understand these properties of the dentate gyrus is to try to integrate experimental data into models, following the famous Hopfield quote: “Build it, and you understand it.” However, when trying this, one faces two major challenges. First, hard quantitative data about cellular properties, structural connectivity, and functional properties of synapses are lacking. Second, the number of individual neurons and synapses to be represented in the model is huge. For example, the dentate gyrus contains ~1 million granule cells in rodents, and ~10 million in humans. Thus, full scale models will be complex and computationally demanding. In this Frontiers Research Topic, we collect important information about cells, synapses, and microcircuit elements of the dentate gyrus. We have put together a combination of original research articles, review articles, and a methods article. We hope that the collected information will be useful for both experimentalists and modelers. We also hope that the papers will be interesting beyond the small world of “dentology,” i.e., for scientists working on other brain areas. Ideally, the dentate gyrus may serve as a blueprint, helping neuroscientists to define strategies to analyze network organization of other brain regions.

This is the 2nd edition of a very well received and popular book that reflects the current state-of-the-art of the ongoing research avenues concerning the hippocampus and processing units bridging the gap between single cell activity, network activity and global brain function. It aims to provide a methodology to anyone interested in developing microcircuit level models of the hippocampus. The book is divided into two thematic areas: (I) Experimental background and (II) Computational analysis. In part I, leading experimental neuroscientists discuss the morphological, physiological and molecular characteristics as well as the connectivity and synaptic properties of the various cell types found in the hippocampus. Behaviour-related ensemble activity patterns of morphologically identified neurons in anesthetized and freely moving animals provide insights on the function of the hippocampal areas. In part II, computational neuroscientists present models of the hippocampal microcircuits at various levels of detail (e.g. single cell level, network level, etc.). Synaptomics and connectomics models of hippocampal structures are initially discussed. Then, network models of memory, rhythm generation and spatial navigation are presented, followed by abstract and biophysical models of synaptic plasticity. Network models of hippocampal implicated disorders (epilepsy and schizophrenia) are then detailed and how their network topologies, connectivities and activities change in these diseases. Finally, two chapters are dedicated to describing simulator environments of single neurons and networks currently used by computational neuroscientists in developing their models and modelling tools to parametrically constrain them. This engaging volume is invaluable to experimental and computational neuroscientists, electrical engineers, physicists, mathematicians and others interested in developing microcircuit models of the hippocampus. Graduate level students and trainees in all of these fields can find this book a significant source of information.

This volume of Progress in Brain Research documents recent developments and research findings in relation to sex and how the brain’s function and behavior differs from men to women. Specific areas include cerebral function, morphology and organization, sexual dimorphism, neural origins,and genetics and epigenetics, as well as potential causes/affects of stress, pain, sexual orientation and identity and other social issues such as distribution of disorders across the sexes and autism. * Informs and updates on all the latest developments in the field * Highlights areas for future research * Contributions from leading authorities and industry experts

The Mouse Nervous System provides a comprehensive account of the central nervous system of the mouse. The book is aimed at molecular biologists who need a book that introduces them to the anatomy of the mouse brain and spinal cord, but also takes them into the relevant details of development and organization of the area they have chosen to study. The Mouse Nervous System offers a wealth of new information for experienced anatomists who work on mice. The book serves as a valuable resource for researchers and graduate students in neuroscience. Systematic consideration of the anatomy and connections of all regions of the brain and spinal cord by the authors of the most cited rodent brain atlases A major section (12 chapters) on functional systems related to motor control, sensation, and behavioral and emotional states A detailed analysis of gene expression during development of the forebrain by Luis Puelles, the leading researcher in this area Full coverage of the role of gene expression during development and the new field of genetic neuroanatomy using site-specific recombinases Examples of the use of mouse models in the study of neurological illness