This book is essentially devoted to analyses of neuronal substrates underlying sleep with low-frequency oscillations, so-called sleep with synchronized electroencephalogram (EEG) or resting sleep, and a series of seizures that preferentially develop during this state of sleep. The reader will find data on intrinsic neuronal properties and network operations in corticothalamic, hippocampal-entorhinal and neuromodulatory systems that control forebrain normal and paroxysmal activities. This brief introductory chapter is not intended to discuss in detail the history of ideas on two bedfellows, sleep and epilepsy, but only to resurrect some of the most important figures and concepts that are directly related to what is discussed at length, essentially at the neuronal level, in the following chapters.

Brain, neurons and sleep across centuries

Different states of vigilance, such as waking and sleep states with or without dreams, have been recognized in ancient cultures. The deafferentation theory of falling asleep dates back to Lucretius, in the first century b.c., was revitalized in the early 19th century by Macnish and Purkinje, and was finally developed during the past century by three major figures of sleep research: Bremer, Moruzzi and Kleitman. As discussed in Chapter 3, the concept of passive or active sleep is a false dilemma as both brain deafferentation from external signals and actively sleep-inducing (humoral and neuronal) factors may lead to sleep, since the presumed actively hypnogenic neurons exert their inhibitory effects on activating neurons in the brainstem and posterior hypothalamus, thus disconnecting the forebrain, as postulated in the passive theory.