In neuroscience, the term gating can assume various meanings depending on the level of analysis. At the level of ionic channels, gating refers to the transition between two or more conformational states of channel proteins. At the neuronal or networks level, gating refers to changes in responsiveness and in inhibitory processes during different behavioral states. In both instances, the causative events and their functional consequences can vary widely. This book focuses on gating in the thalamocortical and amygdalocortical systems.

In the thalamocortical system, gating was often used to describe the blockade of signal transmission from the external world to the cerebral cortex during disconnected states, such as slow-wave sleep. In this monograph, we also discuss evidence that, despite absence of information from the external world, the behavioural state of slow-wave sleep is associated with the processing of internally generated signals and with synaptic plasticity. We also argue that these events may lead to the consolidation of memory traces acquired during the waking state as well as to a form of consciousness expressed by dreaming mentation. The opening of thalamic gates during brain-active states of waking and REM sleep changes the excitability of cortical neurons and leads to different forms of mentation.

In the amygdalocortical system, gating refers to how the transmission of sensory inputs is modulated according to their emotional significance. This process leads to alterations not only in behavioural responsiveness, but also in memory consolidation.