Developmental gene control of brainstem function: views from the embryo.
The respiratory rhythm is generated within the hindbrain reticular formation, rostrally in the vicinity of the facial nucleus and caudally within the vagal/glossopharyngeal domain. This is probably one of the best models to understand how genes have been selected and conserved to control adaptive behaviour in vertebrates. The para-facial region is well understood with respect to the transcription factors that underlie antero-posterior specification of neural progenitors in the embryo. Hox paralogs and Hox-regulating genes kreisler and Krox-20 govern transient formation of developmental compartments, the rhombomeres, in which rhythmic neuronal networks develop. Hox are master genes selecting and coordinating the developmental fate of reticular and motor neurons thereby specifying patterns of motor activities operating throughout life. Neuronal function and development are also tightly linked in the vagal/glossopharyngeal domain. At this level, bdnf acts as a neurotrophin of peripheral chemoafferent neural populations and as a neuromodulator of the central rhythmogenic respiratory circuits. A general view is now emerging on the role of developmental transcription and trophic factors allowing the coordinated integration of different neuronal types to produce, and eventually refine, respiratory rhythmic pattern in a use-dependent manner.
Borday
Caroline
C
UPR 2216 Neurobiologie Génétique et Intégrative, Institut de Neurobiologie Alfred Fessard, CNRS, 1, av de la Terrasse, Gif-sur-Yvette 91198, France.
Wrobel
Ludovic
L
Fortin
Gilles
G
Champagnat
Jean
J
Thaëron-Antôno
Christelle
C
Thoby-Brisson
Muriel
M
D000818:Animals; D030161:Avian Proteins; D001933:Brain Stem / Q000196:embryology*; D019208:Brain-Derived Neurotrophic Factor / Q000502:physiology; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000502:physiology; D051767:Early Growth Response Protein 2; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D051258:MafB Transcription Factor; D051379:Mice; D008954:Models, Biological; D009474:Neurons / Q000378:metabolism; D015513:Oncogene Proteins; D010641:Phenotype; D012249:Rhombencephalon / Q000502:physiology; D013997:Time Factors; D014157:Transcription Factors / Q000502:physiology
D030161:Avian Proteins; D019208:Brain-Derived Neurotrophic Factor; D004268:DNA-Binding Proteins; C497326:EGR2 protein, human; D051767:Early Growth Response Protein 2; C497327:Egr2 protein, mouse; C490407:MAFB protein, human; D051258:MafB Transcription Factor; C490406:Mafb protein, mouse; D015513:Oncogene Proteins; D014157:Transcription Factors; C091157:maf-B protein, chicken