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Subdivisions of chick diencephalic roof plate: Implication in the formation of the posterior commissure
Author(s) -
Stanic Karen,
Montecinos Hernán,
Caprile Teresa
Publication year - 2010
Publication title -
developmental dynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.634
H-Index - 141
eISSN - 1097-0177
pISSN - 1058-8388
DOI - 10.1002/dvdy.22387
Subject(s) - diencephalon , commissure , subcommissural organ , biology , posterior commissure , fasciculation , anatomy , axon guidance , floor plate , axon , neuroscience , microbiology and biotechnology , central nervous system , nucleus
The subcommissural organ (SCO) is a roof plate differentiation located in the caudal diencephalon under the posterior commissure (PC). A role for SCO and its secretory product, SCO‐spondin, in the formation of the PC has been proposed. Here, we provide immunohistochemical evidence to suggest that SCO is anatomically divided in a bilateral region positive for SCO‐spondin that surrounds a negative medial region. Remarkably, axons contacting the lateral region are highly fasciculated, in sharp contrast with the defasciculated axons of the medial region. In addition, lateral axon fascicles run toward the midline inside of tunnels limited by the basal prolongations of SCO cells and extracellular SCO‐spondin. Our in vitro data in collagen gel matrices show that SCO‐spondin induces axonal growth and fasciculation of pretectal explants. Together, our findings support the idea that SCO‐spondin participates in the guidance and fasciculation of axons of the PC. Developmental Dynamics 239:2584–2593, 2010. © 2010 Wiley‐Liss, Inc.