Changing Concepts of Mechanisms of Waking and Sleep States -- Methodology of Morphological and Physiological Substrates Underlying States of Vigilance -- Afferent and Efferent Connections of Brainstem and Forebrain Modulatory Systems -- Neuronal Circuits in the Thalamus, Neocortex, and Hippocampus, Targets of Diffuse Modulatory Systems -- Intrinsic Electrophysiological Properties of Brainstem a…