Activation of XII motoneurons and premotor neurons during various oropharyngeal behaviors.
Neural control of tongue muscles plays a crucial role in a broad range of oropharyngeal behaviors. Tongue movements must be rapidly and accurately adjusted in response to the demands of multiple complex motor tasks including licking/mastication, swallowing, vocalization, breathing and protective reflexes such as coughing. Yet, central mechanisms responsible for motor and premotor control of hypoglossal (XII) activity during these behaviors are still largely unknown. The aim of this article is to review the functional organization of the XII motor nucleus with particular emphasis on breathing, coughing and swallowing. Anatomical localization of XII premotor neurons is also considered. We discuss results concerned with multifunctional activity of medullary and pontine populations of XII premotor neurons, representing a single network that can be reconfigured to produce different oromotor response patterns. In this context, we introduce new data on swallowing-related activity of XII (and trigeminal) motoneurons, and finally suggest a prominent role for the pontine Kölliker-Fuse nucleus in the control of inspiratory-related activity of XII motoneurons supplying tongue protrusor and retrusor muscles.
Gestreau
Christian
C
Laboratoire de Physiologie Neurovégétative, UMR CNRS 6153 INRA 1147, Université Paul Cézanne Aix-Marseille III, Av. Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France. christian.gestreau@univ.u-3mrs.fr
Dutschmann
Mathias
M
Obled
Stéphane
S
Bianchi
Armand Louis
AL
D000818:Animals; D001933:Brain Stem / Q000166:cytology / Q000502:physiology*; D003371:Cough / Q000503:physiopathology; D003679:Deglutition / Q000502:physiology*; D006801:Humans; D009046:Motor Neurons / Q000502:physiology*; D009960:Oropharynx / Q000294:innervation* / Q000502:physiology*; D010507:Periodicity; D012119:Respiration