Ontogeny of central rhythm generation in chicks and rodents
Respiratory Physiology & Neurobiology. 2006-11-01; 154(1-2): 37-46
DOI: 10.1016/j.resp.2006.02.004
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1. Respir Physiol Neurobiol. 2006 Nov;154(1-2):37-46. Epub 2006 Mar 14.
Ontogeny of central rhythm generation in chicks and rodents.
Chatonnet F(1), Borday C, Wrobel L, Thoby-Brisson M, Fortin G, McLean H,
Champagnat J.
Author information:
(1)UPR 2216, Neurobiologie Génétique et Integrative, Institut fédératif de
Neurobiologie Alfred Fessard, C.N.R.S. 1, Avenue de la terrasse, Gif sur Yvette,
91198 Cedex, France.
Recent studies help in understanding how the basic organization of brainstem
neuronal circuits along the anterior-posterior (AP) axis is set by the
Hox-dependent segmentation of the neural tube in vertebrate embryos. Neonatal
respiratory abnormalities in Krox20(-/-), Hoxa1(-/-) and kreisler mutant mice
indicate the vital role of a para-facial (Krox20-dependent, rhombomere 4-derived)
respiratory group, that is distinct from the more caudal rhythm generator called
Pre-Bötzinger complex. Embryological studies in the chick suggest homology and
conservation of this Krox20-dependent induction of parafacial rhythms in birds
and mammals. Calcium imaging in embryo indicate that rhythm generators may derive
from different cell lineages within rhombomeres. In mice, the Pre-Bötzinger
complex is found to be distinct from oscillators producing the earliest neuronal
activity, a primordial low-frequency rhythm. In contrast, in chicks, maturation
of the parafacial generator is tightly linked to the evolution of this primordial
rhythm. It seems therefore that ontogeny of brainstem rhythm generation involves
conserved processes specifying distinct AP domains in the neural tube, followed
by diverse, lineage-specific regulations allowing the emergence of organized
rhythm generators at a given AP level.
DOI: 10.1016/j.resp.2006.02.004
PMID: 16533622 [Indexed for MEDLINE]