Expression of Notch Receptors and Ligands in the Coccygeal Body.

The recent discovery of neural stem cells in the sacrococcygeal end of the filum terminale, the presence of remnants of the most powerful toti-potent stem cell generators and inductors, the primitive streak and node, the existence of the unique non-mutator sacrococcygeal teratomas, and the recent disclosing of neuroimmunomodulatory and hematopoietic roles of Luschka's body, indicate that the sacrococcygeal region is a distinctive anatomic environment rich in stem cells and instructive signals, and that the coccygeal body may constitute a more complex entity than a mere caudal, vascularly-derived glomic anastomosis. Ascribed as an arterial-venous shunt located at the tip of the coccyx and analog to the glomera caudalia in other vertebrates, the glomus coccygeum has recently revealed a complex organ with peculiar 3D topology, broad innervation, catecholamine-synthesizing activity, and neutrophil-formation and lymphopoietic-regulating properties. In the present research work, we sought to start exploring the potential cell-functional roles of the glomus coccygeum by conducting a methodical assessment of the expression of Notch pathway receptors and ligands in the human Luschka's body. Our data indicates that Notch receptors are dynamically and distinctively expressed in the coccygeal body and that Notch ligands are markedly differentially expressed in newborn and adult coccygeal glomi. Our observations suggest that Notch signaling may have relevant roles in glomus coccygeum function and biology.