A progressive loss of neural function and structure, which includes neuron death, occurs through a process known as neurodegeneration. It leads to several diseases, such as Huntington's disease, Parkinson's disease, amyotrophic lateral sclerosis and Alzheimer's disease. These diseases are not reversible and curable, resulting in progressive degeneration and death of neuron cells. The primary risk factor of neurodegeneration is aging. Protein misfolding, genetics, programmed cell death, intracellular mechanisms, etc. are some of the mechanisms by which neurodegeneration occurs. This book is compiled in such a manner, that it will provide in-depth knowledge about the mechanism of neurodegeneration. There has been rapid progress in the understanding of neurodegeneration and neurodegenerative diseases. Scientists and students actively engaged in neuroscience, will find this book full of crucial and unexplored concepts.