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Enteric neural crest stem cells are able to colonize the hindgut of the Dominant megacolon mutant
Author(s) -
W. Y. Chan
Publication year - 2012
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/j.ijdevneu.2012.03.338
Subject(s) - neural crest , hindgut , mutant , biology , citation , stem cell , enteric nervous system , neuroscience , world wide web , microbiology and biotechnology , embryo , computer science , genetics , botany , larva , gene , midgut
In the developing primary somatosensory cortex, thalamocortical axons (TCAs) from individual thalamic barrelloids are almost entirely confined to single barrel clusters, followed by arrangement of cortical layer IV neurons into barrel hollows and septa. Addition to this, unidirectional dendrite formation of barrel neurons toward barrel hollows occurs around P7 for efficient synapse formation with TCAs. To elucidate the molecular mechanism of barrel development, we searched for genes expressed in the barrel cortex, and tested their temporal and spatial expression pattern during early postnatal stage using in situ hybridizasion (ISH). As a result, we found several genes, which show restricted expression only in septa or only in hollow. Among these genes, we focused on Btbd3, BTB/POZ domain containing 3, which belong to same family member with Abrupt that is known to control dendrite formation in Drosophila (Refs. [1,2]). We first revealed that Btbd3 expression starts around P3in cortical layer IV along with TCA innervation, however pattern is not aggregated as barrel. In next few days, TCA terminal aggregate as barrel structure followed by Btbd3 expressing cell aggregation to shape barrel pattern. Next, we revealed that its barrel-like expression is disrupted in the cortex with the abnormal TCA innervation by ablation of infraorbital nerve (ION), which suggest correct input from thalamus requires Btbd3 to form correct barrel structure. Therefore we investigated whether manipulation of Btbd3 expression in the barrel cells via in utero electroporation affects the barrel development. Although no major structural difference was obtained in Btbd3 knockdown barrel cortex, we found dendrite orientation of barrel cell is disrupted in Btbd3 knock down cells. Our results indicate that input from TCA pattern barrel cell dendrite via Btbd3, which is a first evidence of molecular pathway of activity dependent circuit development in the barrel cortex.