An in-depth examination of those components in the brain's reticular core that provide the general mechanisms for integration. This volume offers a dramatic contrast and comparison between the highly precise and specific structures and functions of the motor and sensory systems described in Volume II (Motor Control, 2 volumes, edited by Vernon B. Brooks) and Volume III (Sensory Processes, 2 volumes, edited by Ian Darian-Smith), and the more divergent structures and less functionally constrained effects of the systems of the reticular core. The text proceeds from studies of synaptic transmitter mechanisms in the central and peripheral nervous systems to studies of specific, chemically defined anatomic systems that incorporate these mechanisms and divergent structures into a regulatory ensemble process.