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.

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

[edit] 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]

[edit] 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.

[edit] 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.

[edit] 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]}.

[edit] References

[edit] See also

• Merkel nerve ending
• Merkel cell cancer

[edit] External links

• MeSH A08.800.550.700.500.425
• NIF Search - Merckel Disc Cell via the Neuroscience Information Framework

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. v • d • e