Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

The Hair Follicle: A Specialised UV Receptor in the Human Skin?

The Hair Follicle: A Specialised UV Receptor in the Human Skin? Coat colour changes in polar animals are related to seasonal variation in photic inputs. The present work was performed to study the photoresponses of hair follicular melanocytes in human skin. The melanocytes, being photosensitive cells, can function as UV biosensors, since dendrites extend towards the source of UV light. Fifty-one skin biopsies from the margin of vitiligo were subjected to whole skin organ cultures. These were exposed to a pulse of UV light to study hair bulb melanocytes in vitiligo. It is observed that the melanocytes are seen within the anagen matrix. These melanocytes are poorly dendritic in control and dark-incubated cultures. On UV exposure, they become highly dendritic, the dendrites extending towards the hair shaft in 93.5%. They show prominent catechol oxidase and noradrenaline positivity, all features of UV responsiveness. The melanocytes within the hair follicle are not directly exposed to UV light. The melanocyte dendricity and the alignment of dendrites towards the shaft on UV exposure indicate that the columns of the cells in the hair shaft act as an efficient fibre-optic system, transmitting UV light. Morphologically, the keratinocytes in the hair shaft are arranged in compressed linear columns which resemble the coaxial bundles of commercial fibre-optic strands as is observed in plants. Keratinocytes in the inner and outer sheaths do not show this arrangement. Thus the hair follicle functions as a specialised UV receptor in the skin responding to nuances of photic inputs in human skin. This is reflected in coat colour changes in animals exposed to large variations in day-night cycles. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Neurosignals Karger

The Hair Follicle: A Specialised UV Receptor in the Human Skin?

Iyengar, Bhanu
Neurosignals , Volume 7 (3): 7 – Jan 1, 1998
Download PDF
7 pages

Loading next page...
 
/lp/karger/the-hair-follicle-a-specialised-uv-receptor-in-the-human-skin-YYRF1hl8ic

References (12)

Publisher
Karger
Copyright
© 1998 S. Karger AG, Basel
ISSN
1424-862X
eISSN
1424-8638
DOI
10.1159/000014544
Publisher site
See Article on Publisher Site

Abstract

Coat colour changes in polar animals are related to seasonal variation in photic inputs. The present work was performed to study the photoresponses of hair follicular melanocytes in human skin. The melanocytes, being photosensitive cells, can function as UV biosensors, since dendrites extend towards the source of UV light. Fifty-one skin biopsies from the margin of vitiligo were subjected to whole skin organ cultures. These were exposed to a pulse of UV light to study hair bulb melanocytes in vitiligo. It is observed that the melanocytes are seen within the anagen matrix. These melanocytes are poorly dendritic in control and dark-incubated cultures. On UV exposure, they become highly dendritic, the dendrites extending towards the hair shaft in 93.5%. They show prominent catechol oxidase and noradrenaline positivity, all features of UV responsiveness. The melanocytes within the hair follicle are not directly exposed to UV light. The melanocyte dendricity and the alignment of dendrites towards the shaft on UV exposure indicate that the columns of the cells in the hair shaft act as an efficient fibre-optic system, transmitting UV light. Morphologically, the keratinocytes in the hair shaft are arranged in compressed linear columns which resemble the coaxial bundles of commercial fibre-optic strands as is observed in plants. Keratinocytes in the inner and outer sheaths do not show this arrangement. Thus the hair follicle functions as a specialised UV receptor in the skin responding to nuances of photic inputs in human skin. This is reflected in coat colour changes in animals exposed to large variations in day-night cycles.

Journal

Neurosignals – Karger

Published: Jan 1, 1998

Keywords: UV biosensor; Fibre-optics; Melanocytes; Keratinocytes; Hair follicle; Epidermis

There are no references for this article.