The structure and function of a slowly adapting touch corpuscle in hairy skin

• Published in: The Journal of physiology Vol. 200; no. 3; pp. 763 - 796
• Main Authors: Iggo, A., Muir, A. R.
• Format: Journal Article
• Language: English
• Published: England The Physiological Society 01.02.1969
• Subjects: Adaptation, Physiological; Animals; Axons - physiology; Cats; Electrophysiology; Hair - cytology; Haplorhini; Pressure; Sensory Receptor Cells - cytology; Sensory Receptor Cells - physiology; Skin Physiological Phenomena; Temperature; Time Factors; Touch
• ISSN: 0022-3751; 1469-7793
• DOI: 10.1113/jphysiol.1969.sp008721

1. Slowly adapting cutaneous mechanoreceptors, in the cat and primates, have been studied by histological and neurophysiological methods. 2. Each touch corpuscle is a dome-shaped elevation of the epidermis, whose deepest layer contains up to fifty specialized tactile cells. 3. Nerve plates, enclosed by the tactile cell (Merkel cells), are connected to a single myelinated axon in the dense collagenous core of the corpuscle. 4. The corpuscle generated > 1000 impulses/sec when excited by vertical surface pressure. The response was highly localized and showed a low mechanical threshold, the frequency being dependent upon the velocity and amplitude of the displacement. There was a period of rapid adaptation before a sustained response which might continue for > 30 min. 5. A quantitative analysis of the responses to excitation by displacements of differing amplitude, velocity and duration is included. 6. The discharge of touch corpuscle units evoked by a mechanical stimulus was temperature-sensitive, and was enhanced by a fall in skin temperature.