Alzheimer's disease (AD), the most common form of neurodegenerative disorder in the elderly, is characterised pathologically by extracellular amyloid plaques and intracellular neurofibrillary tangles, pathophysiologically by synaptic dysfunction, and clinically by a progressive decline in cognition. Currently, AD has no cure and its prevalence is predicted to triple by 2050 with the rapid increase in the ageing population, unless more effective treatments are developed. Since the publication of the second book volume, the rapid progress in the research fields of AD and dementia continues through the intensive efforts of research scientists worldwide.This third book volume contains 15 chapters, bringing together a presentation of research frontiers in current AD/dementia research. The topics include molecular genetics of AD, gene expression abnormalities in AD progression, presenilins, taupathy in AD, single - induced(neuron gene expression abnormalities in AD, intracellular A neurodegeneration, roles of lipoprotein receptors in AD onset and progression, cholesterol and tau hyperphosphorylati-on, AD diagnostics and therapeutic strategies, in vivo visualisation of amyloid-like structures, cathepsin B, antiamyloidogenesis and neuroprotection, environmental enrichment, Fragile X mental retardation gene and dementia, category learning in Parkinson's disease, cerebrovascular disease and dementia, and dementia and hypertension.These chapters cover current advances in our understanding of the pathogenic mechanisms underlying AD and dementia, in the diagnosis of early AD and dementia, and in the development of therapeutic agents that target memory-relevant AD pathogenesis. The book will be highly valuable to students and scientists worldwide who are interested in the scientific research progress in AD and dementia.