| Abstract: | Abstract The phylum Placozoa contains the most simply organized multicellular animals: they have a thick lower epithelium and a thin upper epithelium with some single cells sandwiched between these layers. Placozoans are generally considered to have no nerve cells or specialized sensory cells. However, the results of this investigation demonstrate the existence of a specific set of cells which react with antibodies against the neuropeptide family RFamide. The RFamide-positive cells of Trichoplax adhaerens are positioned at some distance along the margin of the animal. |
