Circadian Synchronization of Cognitive Functions

Abstract

Animals, human beings among them, can adapt their behavior to (predictable) temporal fluctuations in the environment (such as day and night alternation, food and water availability, or social contact)by learning and memory processes interacting with an endogenous circadian clock.Behavioral, physiological and biochemical circadian rhythms are crucial for the good mental health of an individual and rely on the integrity and functioning of the Circadian System.The master clock in the suprachiasmatic nucleus synchronizes independent circadian peripheral clocks, localized in other brain areas, organs and tissues, to the appropriate phases, by neural and humoral signals. Thus, circadian clocks orchestrate interactions between the organism's internal processes and the environmentin good health but also in pathological conditions.This chapter makes focus onthe main components of the circadian system, the temporal organization of cognitive functionsat the molecular, biochemical and behavioural levels and their clock-mediated regulation, as well as onfactors that could disrupt the normal functioning of the circadian system and thus, contribute to the etiology of cognitive disorders.