, Volume 85, Issue 1, pp 29–34 | Cite as

Neuron-specific enolase and serotonin in the Merkel cells of conger-eel (Conger conger) epidermis

An immunohistochemical study
  • G. Zaccone


Immunocytochemical techniques were used to investigate the distribution and co-localization of neuronspecific enolase (NSE) and serotonin (5-HT) in the skin of the conger eel, Conger conger. NSE and 5-HT immunoreactivity were found in Merkel cells; these cells were also identified at the electron-microscope level by the presence of characteristic granules and their association with an intraepithelial nerve ending. For the first time, it was demonstrated that Merkel-cell granules of vertebrate skin exhibit in immunoreaction with 5-HT. The production of amines may indicate that the Merkel cells of C. conger have both secretory capabilities and transduction functions.

However, immunocytochemical investigation of the synaptic zones at the electron microscope level will be necessary to confirm this hypothesis.

The present histochemical results suggest that NSE and 4-HT may be marker substances for Merkel cells, and that immunocytochemistry is a useful tool for the light-microscopic localization of these cells.


Serotonin Nerve Ending Microscope Level Electron Microscope Level Immunocytochemical Technique 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Burgess PR, English KB, Horch KW (1974) Patterning in the regeneration of type I cutaneous receptors. J Physiol 236:57–82Google Scholar
  2. Crowe R, Whitear M (1978) Quinacrine fluorescence of Merkel cells in Xenopus laevis. Cell Tissue Res 190:273–283Google Scholar
  3. Fox H, Whitear M (1978) Observations on Merkel cells in amphibians. Biol Cell 32:223–232Google Scholar
  4. Fujita T (1977) Concept of paraneurons. Arch Histol Jpn 40 (Suppl):1–12Google Scholar
  5. Fujita T (1982) New aspects of cells secreting neuropeptides. In: Shizume K, Imura H, Shimizu N (eds.) Procedings of the seventh Asin and Oceanic Congress of Endocrinology. Excerpta Medica, Amsterdam Oxford Princeton, pp 35–43Google Scholar
  6. Gottschaldt KM, Vahle-Hinz C (1981) Merkel cell receptors: structure and transducer function. Science 214:183–186Google Scholar
  7. Gottschaldt KM, Vahle-Hinz C (1982) Evidence against transmitter function of met-enkephalin and chemosynaptic impulse generation in “Merkel cell” mechanoreceptor. Exp Brain Res 45:459–463Google Scholar
  8. Grimelius L (1968) A silver nitrate stain for a2 cells in human pancreatic islets. Acta Soc Med Ups 73:243–270Google Scholar
  9. Gu J, Polak JM, Tapia FJ, Marangos PJ, Pearse AGE (1981) Neuron-specific enolase in the Merkel cells of mammalian skin. The use of specific antibody as a single and reliable histologic marker. Am J Pathol 104:63–68Google Scholar
  10. Hartschuh W, Grube D (1979) The Merkel cell — A member of the APUD cell system? Fluorescence and electron microscopic contribution to the neurotransmitter function of the Merkel cell granules. Arch Dermatol Res 265:115–122Google Scholar
  11. Hartschuh W, Weihe E (1977) The effect of denervation on Merkel cell in cats. Neurosci Lett 5:327–332Google Scholar
  12. Hartschuh W, Weihe E, Büchler M, Helmsstaedter V, Feurle GE, Forssmann WG (1979) Met-enkephalin-like immunoreactivity in Merkel cells. Cell Tissue Res 201:343–348Google Scholar
  13. hartschuh W, Weihe E, Yanaihara N, Reinecke M (1983) Immunohistochemical localization of vasoactive intestinal polypeptide (VIP) in Merkel cells of various mammals: Evidence for a neuromodulator function of the Merkel cell. J Invest Dermatol 81:361–364Google Scholar
  14. Hartschuh W, Reinecke M, Weihe E, Yanaihara N (1984) VIP-immunoreactivity in the skin of various mammals: immunohistochemical, radioimmunological and experimental evidence for a dual localization in cutaneous nerves and Merkel cells. Peptides 5:239–245Google Scholar
  15. Iggo A, Muir AR (1969) The structure and function of a slowly adapting touch corpuscle in hairy skin. J Physiol 200:763–796Google Scholar
  16. Lane EB, Whitear M (1977) On the occurrence of Merkel cells in the epidermis of teleost fishes. Cell Tissue Res 182:235–246Google Scholar
  17. Marangos PJ, Schmechel D (1980) The neurobiology of the brain enolases. In: Youdim MBH, Lovenberg W, Sharman DF, Lagnado JR (eds) Essays in neurochemistry and neuropharmacology. John Wiley & Sons, New York, pp 211–247Google Scholar
  18. Ortonne JP, Darmon M (1984) Cytokeratin recognized by troma I is expressed by Merkel cells and sweat gland cells. Abstracts, fourth conference of the European Society for Comparative Skin Biology, Grenoble, p 27Google Scholar
  19. Schmechel D, Marangos PJ, Brightman M (1978) Neurone-specific endolase is a molecular marker for peripheral and central neuroendocrine cells. Nature 276:834–836Google Scholar
  20. Singh I (1964) A modification of the Masson-Hamperl method for staining of argentaffin cells. Anat Anz 115:81–82Google Scholar
  21. Smith KR (1967) The structure and function of the Haarscheibe. J Comp Neurol 131:459–474Google Scholar
  22. Sternberger LA (1974) Immunocytochemistry. Prentice-Hall, Englewood Cliffs, NJGoogle Scholar
  23. Tachibana T, Ishizcki K, Sakakura Y, Nawa T (1984) Ultrastructural evidence for a possible secretory function of Merkel cells in the barbels of a teleost fish, Cyprinus carpio. Cell Tissue Res 235:695–697Google Scholar
  24. Whitear M (1983) The question of free nerve endings in the epidermis of lower vertebrates. Acta Biol Hung 34:303–319Google Scholar
  25. Whitear M, Zaccone G (1984) Fine structure and histochemistry of club cells in the skin of three species of eel. Z mikrosk Anat Forsch (Leipzig) 98:481–501Google Scholar
  26. Zaccone G (1984) Immunohistochemical demonstration of neuronspecific enolase in the nerve endings and skin receptors of marine eels. Histochem J 16:1231–1236Google Scholar

Copyright information

© Springer-Verlag 1986

Authors and Affiliations

  • G. Zaccone
    • 1
  1. 1.Department of Animal Biology and Marine EcologyMessina UniversityMessinaItaly

Personalised recommendations