ABSTRACT
The human nervous system, its changes during development, adulthood, and old age, and its alterations with disease represent one of the most intriguing challenges of our time. Despite rapidly increasing advances in our understanding, we still have few direct answers to the many questions concerning the activities of its three major divisions [the peripheral, the autonomic, and the central nervous system (CNS)], their interrelationship with each other and with the entire organism. Comparison of the adult and elderly brain, with or without neurologic and psychiatric diseases of old age, reveals specific, morphologic, biochemical, metabolic, and functional differences under normal and diseased states.
