Metabolic Alterations In Neurodegenerative Disorders

Metabolic Drivers and Bioenergetic Components of Neurodegenerative Disease summarizes recent developments in intervention trials in neurodegenerative diseases, particularly Alzheimer’s and Parkinson’s, as well as increasing evidence for the overlap between drivers of metabolic and neurodegenerative disease that impact mitochondrial function and bioenergetics, and subsequently cellular function and pathophysiology. Topics covered include Brain Glucose and Ketone Utilization in Brain Ageing and Neurodegenerative Diseases; the Mitochondrial Hypothesis: Dysfunction, Bioenergetic Defects, and the Metabolic Link to Alzheimer’s Disease; the Metabolic Impact on Neuroinflammation and Microglial Modulation in Neurodegenerative Diseases, the Impact of Circadian and Diurnal Rhythms on Cellular Metabolic Function and Neurodegenerative Diseases, and much more. Summarizes the current status of and future research in Alzheimer’s and Parkinson’s diseases Reviews the impact of the metabolic hypothesis on underlying mechanisms of neurodegenerative diseases

This book aims to provide a state-of-the-art summary of what is currently known about brain glycogen metabolism, detailing the recent advances in our understanding of why glycogen is so critical for normal brain function. The role of glycogen in cellular neurophysiology remains largely unclear and its specific contribution to the energy demand of brain cells is still elusive.Glycogen is the sole cerebral glucose reserve and is emerging as a fundamental component of brain energy metabolism. Pharmacological or genetic manipulation of glycogen metabolism in the brain impairs memory formation and increases susceptibility to epileptic seizures and cortical spreading depression. Glycogen is also directly implicated in abnormal neuronal excitability and mental retardation that characterize brain disorders like Lafora disease and Pompe disease.

There is solid evidence of abnormalities in oxidative / energy metabolism with neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. The papers contained in this book are an attempt to move studies in this area to a deeper, more mechanistic level.

It has become evident over the last years that abnormalities in RNA processing play a fundamental part in the pathogenesis of neurodegenerative diseases. Cellular viability depends on proper regulation of RNA metabolism and subsequent protein synthesis, which requires the interplay of many processes including transcription, pre--‐mRNA splicing, mRNA editing as well as mRNA stability, transport and translation. Dysfunction in any of these processes, often caused by mutations in the coding and non--‐ coding RNAs, can be very destructive to the cellular environment and consequently impair neural viability. The result of this RNA toxicity can lead to a toxic gain of function or a loss of function, depending on the nature of the mutation. For example, in repeat expansion disorders, such as the newly discovered hexanucleotide repeat expansion in theC9orf72 gene found in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD), a toxic gain of function leads to the formation of RNA foci and the sequestration of RNA binding proteins (RBPs). This in return leads to a loss of function of those RBPs, which is hypothesized to play a significant part in the disease progression of ALS and FTD. Other toxicities arising from repeat expansions are the formation of RNA foci, bi--‐directional transcription and production of repeat associated non--‐ATG (RAN) translation products. This book will touch upon most of these disease mechanisms triggered by aberrant RNA metabolism and will therefore provide a broad perspective of the role of RNA processing and its dysfunction in a variety of neurodegenerative disorders, including ALS, FTD, Alzheimer’s disease, Huntington’s disease, spinal muscular atrophy, myotonic dystrophy and ataxias. The proposed authors are leading scientists in the field and are expected to not only discuss their own work, but to be inclusive of historic as well as late breaking discoveries. The compiled chapters will therefore provide a unique collection of novel studies and hypotheses aimed to describe the consequences of altered RNA processing events and its newest molecular players and pathways.

Numerous studies have established a clear connection between neuronal oxidative stress and several neurodegenerative diseases, with consequential damages to lipids, proteins, nucleic acids, etc. In addition, several modifications indicative of oxidative stress have been described in association with neurons, neurofibrillary tangles and senile plaques in Alzheimer's disease, including advanced glycation end products and free carbonyl oxidation.Oxidative damage and antioxidant responses are now well characterized, but sources of damaging free radicals are yet to be fully understood. Evidences of alteration in metal ions metabolism have been reported in various diseases like Alzheimer's, Wilson, Menkes, Prion, Pick, Huntington disease, epilepsy and other pathological events. Thus, metal ions play a pivotal role in neurodegenerative phenomena.Chelation therapy is still in the early days of its development, but research in this area could lead to new products that could revolutionize treatment. Two international conferences on ?Metals and the Brain: From Neurochemistry to Neurodegeneration? (Padova, Italy, 2000 and Fez, Morocco, 2002) were recently held to discuss the role of metal ions in neurophysiopathology. A third will be held in 2005 in Johannesburg, South Africa.This book follows the same train of thought as those conferences, in order to highlight the unquestionable importance of metal ions in the research on the neurophysiopathology of neurodegenerative diseases. The excellent reputation of the scientists who have contributed to this project ensures the quality of the chapters presented here, and hopefully this will help spur new research initiatives in the field, which is still in its infancy.

The editor of this volume, having research interests in the field of ROS production and the damage to cellular systems, has identified a number of enzymes showing ·OH scavenging activities details of which are anticipated to be published in the near future as confirmatory experiments are awaited. It is hoped that the information presented in this book on NDs will stimulate both expert and novice researchers in the field with excellent overviews of the current status of research and pointers to future research goals. Clinicians, nurses as well as families and caregivers should also benefit from the material presented in handling and treating their specialised cases. Also the insights gained should be valuable for further understanding of the diseases at molecular levels and should lead to development of new biomarkers, novel diagnostic tools and more effective therapeutic drugs to treat the clinical problems raised by these devastating diseases.

This edition of Advances in Neurobiology brings together experts in the emerging field of Systems Neuroscience to present an overview of this area of research. Topics covered include: how different neural circuits analyze sensory information, form perceptions of the external world, make decisions, and execute movements; how nerve cells behave when connected together to form neural networks; the relationship between molecular and cellular approaches to understanding brain structure and function; the study of high-level mental functions; and studying brain pathologies and diseases with Systems Neuroscience. A hierarchy of biological complexity arises from the genome, transcriptome, proteome, organelles, cells, synapses, circuits, brain regions, the whole brain, and behaviour. The best way to study the brain, the most complex organ in the body composed of 100 billion cells with trillions of interconnections, is with a Systems Biology approach. Systems biology is an inter-disciplinary field that focuses on complex interactions within biological systems to reveal 'emergent properties' - properties of cells and groups of cells functioning as a system whose actual and theoretical description is only possible using Systems Biology techniques.