mise à jour du
25 janvier 2010
Liste des orateurs
Les résumés par thème
Programme et horaires pdf
FICY dans les médias
Index du site
Recherche par thèmes
Recherche par mot du site :


avec l'aide de


Première conférence internationale sur le bâillement
First International Conference on Yawning
Paris 24 - 25 juin 2010
Galerie des Photos de FICY
Yawning a cathartic function of the reticular system
Yawning and the reticular formation Askenasy J, Askenasy E
Jean Askenasy and Enosh Askenasy
Neurology, University Jerusalemn, Israel.
The act of yawning begins during fetal life. The complex biochemistry involved in this action includes many enzymes and neurotransmitters, including: dopamine, acetylcholine, muscarine, histamine, adenosine, serotonin, nitric oxid, adrenocorticotropic hormine, oxytocin, alpha-melanocyte hormone, opioids and gammaaminobutyric acid.
An early research into the physiology of yawning was conducted by Charcot. His famous case was a woman with relentless yawning who was hospitalized for months in Salpetriere hospital. This patient presented with a yawning frequency of 8 yawns per minute, and Charcot noted that although her breathing pattern was severely disturbed her ventilation was not reduced.
Charcot then realized that the patient's yawning was functioning as deep inspirations replacing normal breathing movements (breathing through yawning). A single yawn can therefore be viewed as an isolated act of hyperventilation in which the oxygen saturation is increased and the PCO2 reduced.
Yawning is a signal initiated by the reticular system and brough to our consciousness, that a change in the functional state of the nervous system occurs and need help.
Any change in the steady state as perceived by the brain provokes a reaction by the reticular formation. Therefore a yawn may be triggered by a diverse array of states which represent a change in situation: boredom, sadness, surprise, suffering, fatigue, stress, somnolence...
The reticular system's anatomy of intense proximity (under 2 inches) of both activating and inhibitory neuronal networks may explain why yawning appears in situation which are seemingley paradoxal such as boredom and excitation.
Inaccuracies in the harmonic regulation function occurs on pathologic basis, at different levels of the central nervous system, such as the cortical, limbic, hypothalamic and autonomic nervous system, but always involving the essential regulator "the reticular network".