Current considerations about Merkel cells

Area of Science:

• Cell biology
• Dermatology
• Neuroscience

Background:

• Merkel cells, discovered in 1875, reside in the epidermis.
• Characterized by dense-core granules, plasma membrane spines, and cytokeratin filaments.
• Origin (epidermal vs. neural crest) and function remain debated.

Purpose of the Study:

• To review and compare Merkel cell structure and function across vertebrates.
• To investigate the stimuli Merkel cells can perceive.
• To clarify the controversial roles of Merkel cells.

Main Methods:

• Review of existing literature utilizing electron microscopy, laser microscopy, and immunohistochemistry.
• Comparative analysis of Merkel cell characteristics in various vertebrate species.
• Exploration of proposed mechanosensory and endocrine functions.

Main Results:

• Merkel cells possess structures suggesting epidermal origin, though not universally accepted.
• Associated nerve terminals imply mechanoreceptor function; non-associated cells suggest endocrine roles.
• The specific stimuli perceived by Merkel cells require further investigation.

Conclusions:

• Merkel cells exhibit complex structural and functional characteristics.
• Their role as mechanoreceptors or endocrine cells is context-dependent.
• Further research is needed to elucidate the full range of stimuli Merkel cells perceive.