Neural basis of drug-induced yawning

In a study of human yawning Robert Provine (1986) remarked that yawning is a prominent stereotyped action pattem and releasing stimulus which “does not deserve its current status as a minor behavioural curiosity”. Indeed, “yawning may have the dubious distinction of being the least understood, common, human behaviour”. In contrast, a large body of experimental data has been collected during the past 30 years on drug-induced yawning in animals (particularly rodents). In this chapter we consider the neural basis of drug-induced yawning in rodents and discuss the relevance of this pharmacological phenomenon to “spontaneous” yawning in animals and man.