Specialized Connexions between Nerve Cells and Mesenchymal Cells in Ctenophores

Abstract

THE mesogloea in ctenophores, as in certain coelenterates^1,2, is essentially a third cell layer containing muscle cells, nerve cells and so-called “amoeboid” cells^3,4. Our unpublished studies on Beroe suggest that the “amoeboid” cells do indeed undergo a migratory phase during regeneration, but that there is no evidence of migration in the normal animal. Histological preparations show the cells with very long, thin processes connected together in the form of a net. We prefer to call them “mesenchymal” cells. We now have evidence from electron microscopy of specialized junctions between these mesenchymal cells and neighbouring muscle and nerve cells in Beroe forskälii and B. ovata.