Verification and characterisation of human digital Ruffini's sensory corpuscles.

Area of Science:

• Neuroscience
• Dermatology
• Histology

Background:

• Ruffini's corpuscles are known sensory structures in various tissues.
• Their presence in glabrous digital skin has been physiologically suggested but not anatomically confirmed.
• Understanding their distribution and characteristics in digital skin is crucial for sensory research.

Purpose of the Study:

• To investigate and confirm the occurrence of Ruffini's corpuscles in human glabrous digital skin.
• To analyze the density, distribution, and immunohistochemical profile of these corpuscles.
• To determine the cellular origin of Ruffini's corpuscles in this specific location.

Main Methods:

• Analysis of 372 human digital skin sections from 186 individuals.
• Immunohistochemical staining for S100 protein, neuron-specific enolase, and neurofilament proteins.
• Assessment of CD34 and Glut1 expression to identify cellular origins.

Main Results:

• Ruffini's corpuscles were detected at low densities (<0.3/mm²).
• Density varied across fingers (F4>F3>F2>F1>F5) and absolute counts (F2>F1>F3>F4>F5).
• Immunohistochemistry confirmed an endoneurial origin (S100+, NSE+, NF+, CD34+, Glut1-).

Conclusions:

• This study confirms the existence of Ruffini's corpuscles in human glabrous digital skin.
• These corpuscles are present at very low densities and exhibit specific distribution patterns.
• Their immunohistochemical profile aligns with other dermal sensory corpuscles, indicating an endoneurial origin.