Structural diversity of chondroitin sulfate glycosaminoglycans and retinal pathway formation

Chondroitin sulfate glycosaminoglycans (CSs) inhibit axonal growth of retinal ganglion cells to keep territory of their growth on the diencephalon, the optic tract. CSs' chains contains higher structural diversities; however, it is not well known function of their diversity. We prepared polystyrene beads with CSs-phosphatydyl ethanolamine derivatives adhered on their surface, and have developed assay for growth cones behaviors encountering the CSs beads on time-lapse movies; the assay enables us to examine effects of CSs and their structural diversity on the growth cone behaviors. Growth cones behaviors of the retinal axons were classified against CSs' beads in three groups: (1) no change, (2) avoidance turning, and (3) retraction. Percentages of growth cone 'retraction' differ between CS-E and CS-A beads, indicating that the retinal growth cones distinguish between the beads by CSs' structural diversity. Presently, we have been confirming the results; it is expecting to examine relationship between structural diversity of CSs and its functional specificity on growth cones' behavior of the retinal axons.