Merkel cell: Information from Answers.com

Neuron: Merkel Cell
NeuroLex ID	nifext_87
This box: view • talk

Merkel cells are oval receptor cells found in the skin of vertebrates that have synaptic contacts with somatosensory afferents. They are associated with the sense of light touch discrimination of shapes and textures. They can turn malignant and form the skin tumor known as Merkel cell carcinoma.

1 History
2 Location
3 Function
4 Developmental origin
5 References
6 See also
7 External links

History

They were given their name in 1878 by Robert Bonnet^[1] after the 19th century German anatomist Friedrich Sigmund Merkel who was the first to fully describe them in 1875.^[2]

Location

Merkel cells are found in the skin and some parts of the mucosa (stratum germinativum) of all vertebrates. In mammalian skin, they are clear cells found in the stratum basale (at the bottom of sweat duct ridges) of the epidermis approximately 10 µm in diameter. They also occur in epidermal invaginations of the plantar foot surface called rete ridges.^[3] Most often, they are associated with sensory nerve endings, when they are known as Merkel nerve endings (also called a Merkel cell-neurite complex). They are associated with slowly adapting (SA1) somatosensory nerve fibers.

Function

Friedrich S. Merkel referred to these cells as Tastzellen or "touch cells" but this proposed function has been controversial as it has been hard to prove. However, genetic knockout mice have recently shown that Merkel cells are essential for the specialized coding by which afferent nerves resolve fine spatial details.^[4] Merkel cells are sometimes considered APUD cells because they contain dense core granules, and thus may also have a neuroendocrine function.

Developmental origin

The origin of Merkel cells has been debated for over 20 years. Evidence from skin graft experiments in birds implies that they are neural crest derived, but experiments in mammals now demonstrate an epidermal origin.^[5] ^[6].

References

^ Merkel's cells Who named it
^ Merkel FS. (1875). Tastzellen und Tastkörperchen bei den Hausthieren und beim Menschen. Archiv für mikroskopische Anatomie, 11: 636-652.
^ Halata Z, Grim M, Bauman KI. (2003). Friedrich Sigmund Merkel and his "Merkel cell", morphology, development, and physiology: review and new results. Anat Rec A Discov Mol Cell Evol Biol. 271(1):225-39. PMID 12552639
^ Maricich SM, Wellnitz SA, Nelson AM, Lesniak DR, Gerling GJ, Lumpkin EA, Zoghbi HY. (2009). Merkel Cells Are Essential for Light-Touch Responses. 324: 1580 - 1582. doi:10.1126/science.1172890
^ Morrison KM, Miesegaes GR, Lumpkin EA, Maricich SM. (2009). Mammalian Merkel cells are descended from the epidermal lineage. Dev Biol. 2009 Sep 25. PMID 19782676
^ Van Keymeulen A, Mascre G, Youseff KK, Harel I, Michaux C, De Geest N, Szpalski C, Achouri Y, Bloch W, Hassan BA, Blanpain C. (2009). Epidermal progenitors give rise to Merkel cells during embryonic development and adult homeostasis. J Cell Biol. 187(1):91-100. PMID 19786578

External links

v • d • e Nervous system, receptors: somatosensory system (GA 10.1059)

Medial lemniscus	Touch/mechanoreceptors: Pacinian corpuscles – vibration • Meissner's corpuscles – light touch • Merkel's discs – pressure • Ruffini endings - stretch • Free nerve endings – pain • Hair cells • Baroreceptor Proprioception: Golgi organ – tension/length • Muscle spindle – velocity of change (Intrafusal muscle fiber • Nuclear chain fiber • Nuclear bag fiber)

Spinothalamic tract	Pain: Nociception and Nociceptors Temperature: Thermoreceptors

v • d • e Nervous system: Sensory systems / senses (TA A15)

Special senses	Visual system/sight Auditory system/hearing Chemoreception (Olfactory system/smell • Gustatory system/taste)

Touch	Pain • Heat • Balance (Equilibrioception) • Mechanoreception (Pressure, vibration, proprioception)

Other	Sensory receptor

This anatomy article is a stub. You can help Wikipedia by expanding it.

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)

Donate to Wikimedia

	Where can you get facts about Angela Merkel? Read answer...
	Who is Angela Merkel and why is she famous? Read answer...
	When was merkel angela born? Read answer...

	What is the melanocytes and the Merkel cells located?
	How do you know if merkel cell is cancerous?
	What is the function of a merkel cell?

		Medical Glossary. © 2006 through a partnership of Answers Corporation. All rights reserved. Read more
		Wikipedia. This article is licensed under the Creative Commons Attribution/Share-Alike License. It uses material from the Wikipedia article "Merkel cell". Read more

Merkel cell

Contents