Synaptic Modifications in Hippocampal CA3 Pyramidal Cells in an Alzheimer's Mouse Model PDF Download

Author: Pei Zhang
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
Memory encoding is thought to proceed from durable changes in the activity of synaptic circuits, leading to the storage of patterns of electrical events in a sparsely distributed ensemble of neurons. Located at the entry level of hippocampal circuitry, the CA3 region is thought to be important for episodic memory encoding, especially at the initial stage of acquisition, by presumably developing an instant representation of a context. CA3 pyramidal cells receive a variety of inputs, among which the mossy fiber (Mf) inputs draw special attention for their peculiar structure and unique synapti...

Author: Ricardo Andres Valenzuela
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 165

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Book Description
Down Syndrome and Fragile X Syndrome are disorders of mental retardation that are characterized by cognitive impairments and changes to other physical characteristics. A goal in the study of these diseases has been to understand the mechanisms that underlie the cognitive impairments present in these two disorders of mental retardation. A great deal of effort has been made to study synaptic function and structure in these disorders of mental retardation in order to determine whether there are any alterations present. Alterations to synaptic structure and function present during these disorders may give insight to the neural basis of the cognitive impairments that are characteristic of this disorder of mental retardation. An area of the brain that may be affected by these disorders is the hippocampus. This area of the brain has been extensively studied for its role in memory and alterations to synaptic function and structure may underlie some of the memory deficits present in these disorders of mental retardation. Both Down Syndrome patients and Fragile X Syndrome patients have deficits in their performance on memory tests. Down Syndrome patients also have a reduction in the number of neurons present in the hippocampus (Carlesimo et al., 1997). Fragile X Syndrome patients had structural abnormalities in the hippocampus including an enlargement of ventricular spaces (Jakala et al., 1997). Synaptic function and structure in the hippocampus of mouse models of Down Syndrome and Fragile X Syndrome were studied in order to determine this region of the brain was affected. Electrophysiology recordings in area CA3 of the hippocampus of the Ts65Dn Down Syndrome mouse model indicated there were disruptions to synaptic connectivity, decreases in excitatory and inhibitory synaptic transmission, and also a reduction in intrinsic interneuron activity. Imaging studies of CA3 in the Ts65Dn mouse did not show alterations to the number of synapses or structure of synapses suggesting that the alterations found with electrophysiology recordings are the result of functional changes to synapses. Electrophysiology study of the hippocampus in mouse models of Fragile X Syndrome has shown that inhibitory function was generally intact but that excitatory axons from neurons that lacked the Fragile X Mental Retardation Protein (FMRP) were less competitive at forming synapses in a mosaic expression system of the Fmr1 gene the lack of which causes the disease. These studies indicate that alterations to synaptic structure and function are present in the hippocampus of these mouse models of mental retardation. The differences however, were not the same in Down Syndrome and Fragile X Syndrome mouse models. Nonetheless, it is possible that the changes to synaptic function found in both of these mouse models leads to altered network function in the hippocampus which may, in turn, be the underlying cause of the memory deficits present in these disorders of mental retardation. The data presented in these studies indicate that the study of these mouse models of mental retardation can give insight to alterations caused by these disorders of mental retardation which may also lead to the development of new treatments.

Author: Peter A. Brennan
Publisher: Elsevier Health Sciences
ISBN: 0702073881
Category : Medical
Languages : en
Pages : 891

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Book Description
Written and edited by expert surgeons in collaboration with a world-renowned anatomist, this exquisitely illustrated reference consolidates surgical, anatomical and technical knowledge for the entire human body in a single volume. Part of the highly respected Gray's 'family,' this new resource brings to life the applied anatomical knowledge that is critically important in the operating room, with a high level of detail to ensure safe and effective surgical practice. Gray's Surgical Anatomy is unique in the field: effectively a textbook of regional anatomy, a dissection manual, and an atlas of operative procedures – making it an invaluable resource for surgeons and surgical trainees at all levels of experience, as well as students, radiologists, and anatomists. - Brings you expert content written by surgeons for surgeons, with all anatomical detail quality assured by Lead Co-Editor and Gray's Anatomy Editor-in-Chief, Professor Susan Standring. - Features superb colour photographs from the operating room, accompanied by detailed explanatory artwork and figures from the latest imaging modalities - plus summary tables, self-assessment questions, and case-based scenarios – making it an ideal reference and learning package for surgeons at all levels. - Reflects contemporary practice with chapters logically organized by anatomical region, designed for relevance to surgeons across a wide range of subspecialties, practice types, and clinical settings – and aligned to the requirements of current trainee curricula. - Maximizes day-to-day practical application with references to core surgical procedures throughout, as well as the 'Tips and Anatomical Hazards' from leading international surgeons. - Demonstrates key anatomical features and relationships that are essential for safe surgical practice - using brand-new illustrations, supplemented by carefully selected contemporary artwork from the most recent edition of Gray's Anatomy and other leading publications. - Integrates essential anatomy for robotic and minimal access approaches, including laparoscopic and endoscopic techniques. - Features dedicated chapters describing anatomy of lumbar puncture, epidural anaesthesia, peripheral nerve blocks, echocardiographic anatomy of the heart, and endoscopic anatomy of the gastrointestinal tract – as well as a unique overview of human factors and minimizing error in the operating room, essential non-technical skills for improving patient outcomes and safety.

Author: Per Andersen
Publisher: Oxford University Press
ISBN: 9780195100273
Category : Medical
Languages : en
Pages : 892

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Book Description
The hippocampus is one of a group of remarkable structures embedded within the brain's medial temporal lobe. Long known to be important for memory, it has been a prime focus of neuroscience research for many years. The Hippocampus Book promises to facilitate developments in the field in a major way by bringing together, for the first time, contributions by leading international scientists knowledgeable about hippocampal anatomy, physiology, and function. This authoritative volume offers the most comprehensive, up-to-date account of what the hippocampus does, how it does it, and what happens when things go wrong. At the same time, it illustrates how research focusing on this single brain structure has revealed principles of wider generality for the whole brain in relation to anatomical connectivity, synaptic plasticity, cognition and behavior, and computational algorithms. Well-organized in its presentation of both theory and experimental data, this peerless work vividly illustrates the astonishing progress that has been made in unraveling the workings of the brain. The Hippocampus Book is destined to take a central place on every neuroscientist's bookshelf.

Author: Robert Vink
Publisher: University of Adelaide Press
ISBN: 0987073052
Category : Medical
Languages : en
Pages : 354

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Book Description
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.

Author: Nancy Y. Ip
Publisher: Springer Science & Business Media
ISBN: 0387788875
Category : Medical
Languages : en
Pages : 326

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Book Description
Cyclin Dependent Kinase 5 provides a comprehensive and up-to-date collection of reviews on the discovery, signaling mechanisms and functions of Cdk5, as well as the potential implication of Cdk5 in the treatment of neurodegenerative diseases. Since the identification of this unique member of the Cdk family, Cdk5 has emerged as one of the most important signal transduction mediators in the development, maintenance and fine-tuning of neuronal functions and networking. Further studies have revealed that Cdk5 is also associated with the regulation of neuronal survival during both developmental stages and in neurodegenerative diseases. These observations indicate that precise control of Cdk5 is essential for the regulation of neuronal survival. The pivotal role Cdk5 appears to play in both the regulation of neuronal survival and synaptic functions thus raises the interesting possibility that Cdk5 inhibitors may serve as therapeutic treatment for a number of neurodegenerative diseases.

Author: Philippe Taupin
Publisher: Nova Publishers
ISBN: 9781600219146
Category : Medical
Languages : en
Pages : 156

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Book Description
The hippocampus , the Greek word for seahorse, is one of the most fascinating and intriguing regions of the mammalian brain. It is a bilateral incurved seahorse-shaped structure of the cerebral cortex. The hippocampus has a highly distinctive morphology. It is composed of two regions, the dentate gyrus (DG) and the Cornu Ammonis (CA). The nerve cells of the main layer of the DG and CA regions, the granule cells and pyramidal cells respectively, are organised in a tri-synaptic lamellaire circuit. The granule and pyramidal cells are glutamatergic excitatory. The granule cells elicit unique histological, biochemical, developmental, physio- and pathological features. The hippocampus is also an area of the brain that elicits a high degree of plasticity, like synaptic and phenotypic plasticity. It is also one of the few regions of the brain where neurogenesis, the generation of new nerve cells, occurs throughout adulthood. The hippocampus is involved in physio-and pathological processes, like learning and memory.

Author: A.D. Roses
Publisher: Springer Science & Business Media
ISBN: 3642801099
Category : Medical
Languages : en
Pages : 208

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Book Description
There is now considerable genetic evidence that the type 4 allele of the apolipoprotein E gene is a major susceptibility factor associated with late-onset Alzheimer's disease, the common form of the disease defined as starting after sixty years of age. The role of apolipoprotein E in normal brain metabolism and in the pathogenesis of Alzheimer's disease are new and exciting avenues of research. This book, written by the most outstanding scientists in this new filed, is the first presentation of results concerning the implications of apolipoprotein E on the genetics, cell biology, neuropathology, biochemistry, and therapeutic management of Alzheimer's disease.

Author: Jeffrey Noebels
Publisher: OUP USA
ISBN: 0199746540
Category : Medical
Languages : en
Pages : 1258

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Book Description
Jasper's Basic Mechanisms, Fourth Edition, is the newest most ambitious and now clinically relevant publishing project to build on the four-decade legacy of the Jasper's series. In keeping with the original goal of searching for "a better understanding of the epilepsies and rational methods of prevention and treatment.", the book represents an encyclopedic compendium neurobiological mechanisms of seizures, epileptogenesis, epilepsy genetics and comordid conditions. Of practical importance to the clinician, and new to this edition are disease mechanisms of genetic epilepsies and therapeutic approaches, ranging from novel antiepileptic drug targets to cell and gene therapies.

Author: Jesus Avila
Publisher: Frontiers E-books
ISBN: 288919261X
Category : Medicine (General)
Languages : en
Pages : 114

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Book Description
Neurofibrillary tangles (NFTs) composed of intracellular aggregates of tau protein are a key neuropathological feature of Alzheimer’s Disease (AD) and other neurodegenerative diseases, collectively termed tauopathies. The abundance of NFTs has been reported to correlate positively with the severity of cognitive impairment in AD. However, accumulating evidences derived from studies of experimental models have identified that NFTs themselves may not be neurotoxic. Now, many of tau researchers are seeking a “toxic” form of tau protein. Moreover, it was suggested that a “toxic” tau was capable to seed aggregation of native tau protein and to propagate in a prion-like manner. However, the exact neurotoxic tau species remain unclear. Because mature tangles seem to be non-toxic component, “tau oligomers” as the candidate of “toxic” tau have been investigated for more than one decade. In this topic, we will discuss our consensus of “tau oligomers” because the term of “tau oligomers” [e.g. dimer (disulfide bond-dependent or independent), multimer (more than dimer), granular (definition by EM or AFM) and maybe small filamentous aggregates] has been used by each researchers definition. From a biochemical point of view, tau protein has several unique characteristics such as natively unfolded conformation, thermo-stability, acid-stability, and capability of post-translational modifications. Although tau protein research has been continued for a long time, we are still missing the mechanisms of NFT formation. It is unclear how the conversion is occurred from natively unfolded protein to abnormally mis-folded protein. It remains unknown how tau protein can be formed filaments [e.g. paired helical filament (PHF), straight filament and twisted filament] in cells albeit in vitro studies confirmed tau self-assembly by several inducing factors. Researchers are still debating whether tau oligomerization is primary event rather than tau phosphorylation in the tau pathogenesis. Inhibition of either tau phosphorylation or aggregation has been investigated for the prevention of tauopathies, however, it will make an irrelevant result if we don’t know an exact target of neurotoxicity. It is a time to have a consensus of definition, terminology and methodology for the identification of “tau oligomers”.