TY - CHAP M1 - Book, Section TI - BIOLOGY OF NEUROLOGIC DISEASES A1 - Hauser, Stephen L. A1 - Prusiner, Stanley B. A1 - Beal, M. Flint A2 - Hauser, Stephen L. A2 - Josephson, S. Andrew PY - 2018 T2 - Harrison's Neurology in Clinical Medicine, 4e AB - The human nervous system is the organ of consciousness, cognition, ethics, and behavior; as such, it is the most intricate structure known to exist. More than one-third of the 23,000 genes encoded in the human genome are expressed in the nervous system. Each mature brain is composed of 100 billion neurons, several million miles of axons and dendrites, and >1015 synapses. Neurons exist within a dense parenchyma of multifunctional glial cells that synthesize myelin, preserve homeostasis, and regulate immune responses. Measured against this background of complexity, the achievements of molecular neuroscience have been extraordinary. This chapter reviews selected themes in neuroscience that provide a context for understanding fundamental mechanisms underlying neurologic disorders. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/04/19 UR - neurology.mhmedical.com/content.aspx?aid=1145768936 ER -