title: Chondroitin sulfate disrupts axon pathfinding in the optic tract and alters growth cone dynamics.
abstract: Little is known about the cues that guide retinal axons across the diencephalon en route to their midbrain target, the optic tectum. Here we show that chondroitin sulfate proteoglycans are differentially expressed within the diencephalon at a time when retinal axons are growing within the optic tract. Using exposed brain preparations, we show that the addition of exogenous chondroitin sulfate results in retinal pathfinding errors. Retinal axons disperse widely from their normal trajectory within the optic tract and extend aberrantly into inappropriate regions of the forebrain. Time-lapse analysis of retinal growth cone dynamics in vivo shows that addition of exogenous chondroitin sulfate causes intermittent stalling and increases growth cone complexity. These results suggest that chondroitin sulfate may modulate the guidance of retinal axons as they grow through the diencephalon towards the optic tectum.
authors.affiliation: University of California San Diego, Department of Biology, La Jolla, CA 92093, USA.
authors.forename: Andreas
authors.initials: A
authors.lastname: Walz
authors.forename: Richard B
authors.initials: RB
authors.lastname: Anderson
authors.forename: Atsushi
authors.initials: A
authors.lastname: Irie
authors.forename: Chi-Bin
authors.initials: CB
authors.lastname: Chien
authors.forename: Christine E
authors.initials: CE
authors.lastname: Holt
mesh_terms: D000818:Animals; D001369:Axons / Q000187:drug effects / Q000378:metabolism*; D002809:Chondroitin Sulfates / Q000096:biosynthesis* / Q000494:pharmacology; D004625:Embryo, Nonmammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000502:physiology; D020439:Growth Cones / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D011247:Pregnancy; D014795:Visual Pathways / Q000187:drug effects / Q000196:embryology / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D002809:Chondroitin Sulfates