Meeting Abstract
29.5 Monday, Jan. 4 Echinoderm nervous system as an emerging model to study neural regeneration MASHANOV, V.S.**; ZUEVA, O.R.; HEINZELLER, T.; GARCIA-ARRARAS, J.E.; University of Puerto Rico; University of Puerto Rico; LMU, Munich; University of Puerto Rico mashanovvlad@googlemail.com
The phylum Echinodermata is of particular interest to a regeneration researcher for at least two main reasons. First, the phylum belongs to the monophyletic group Deuterostomia, which also includes our own phylum, the Chordata. Second, echinoderms are well known for their capacity to regenerate almost any part of their body following injury. However, the echinoderm nervous system has been largely ignored so far as a subject of serious research. The main reason behind that is the set of peculiar features, which has been attributed to the nervous system, such as the pentaradial symmetry, subdivision into anatomically separated ectoneural and hyponeural subsystems, possible mesodermal origin of the latter. However, our recent research in organization, development, and regeneration of the main nerve cords in sea cucumbers has refuted many of the misconceptions about the echinoderm nervous system and showed that there is much more in common between the nervous system in echinoderms and chordates than was thought previously. Among the most intriguing findings is the organization and emerging functional role of echinoderm glia. Employing a combination of electron microscopy and immunocytochemical techniques, we have demonstrated that the echinoderm glial cells share morphological and antigenic properties with chordate radial glia and, most intriguingly, play a key role in both the post-traumatic neurogenesis and normal cell turnover, as do glial cells in vertebrate CNS regenerators. Further studies of the nervous system regeneration in echinoderms, with special reference to the glial reaction, will most probably provide a new understanding of what makes the CNS regeneration successful in echinoderms and lower chordates and why it does not readily occur in higher vertebrates, including human.
