Premium
[P77]: Effect of ethanol on oxidative stress in the neonatal rat cerebellum
Author(s) -
Kane C.,
Chang J.,
Garg T.,
Han L.
Publication year - 2006
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.2006.09.139
Subject(s) - citation , library science , medical science , medicine , computer science , medical education
TAG-1 is a GPI-anchored cell adhesion molecule, expressed by neurons and myelinating glial cells. In the adult, TAG-1 controls axon–glia contact at the juxta-paranodal regions of myelinated fibers, contributing to the organization of axonal domains at the node of Ranvier. During development, the transient expression of TAG-1 by axons in several fascicles of the embryonic brain suggests a role for TAG-1 in axono-axonal and/or axono-glial interactions during development. To investigate this possible role of TAG-1, we focused our study on the embryonic optic nerve where astroglial and oligodendroglial cells develop in contact with the axons, and where TAG-1 is strongly expressed by retinal ganglion cells (RGCs) during the period of axonal growth and targeting. First, we examined the effect of TAG-1 on RGC axons and glial precursor cells in vitro. TAG-1 protein promoted RGC axon outgrowth, similar to other adhesion molecules such as L1 and NrCAM. Time-lapse videomicroscopy imaging of RGC axons growing on TAG-1 cells will allow us to discriminate between the possible effects of TAG1 on growth cone extension, formation of collaterals and axon fasciculation. The trophic and adhesive responses of developing glial cells were also changed in contact with TAG-1. Recombinant TAG-1 protein strongly promoted the survival and adhesion, but not the proliferation, of astroglial and oligodendroglial precursor cells. Secondly, we used TAG-1 deficient mice to examine the consequences of TAG1 loss on the morphology of axons and glial cells in the optic nerve. Electron-microscopy analysis of hetero and homozygous animals showed structural anomalies in axon compaction and the distribution of glial cells between the axonal bundles. The mapping of retino-collicular projections, as well as the analysis of glial cell differentiation in the optic nerve will address the final functional impact of TAG-1 loss on the visual pathway. Altogether our present findings indicate that TAG-1 acts on the development of both RGC axons and glial cells, and suggest that TAG-1 would mediate axon–glial cells interactions required for the proper development of the optic nerve.