Page 119

Surber, C. Humbert, P. Abels, C., & Maibach, H. (eds.)(2018). The Acid Mantle: A Myth or an Essential Part of Skin Health? Current Problems

population of specialised mechanosensory nociceptors.

in Dermatology, 54:1-10. doi: 10.1159/000489512. Epub 2018 Aug 20.

A new population of specialised mechanosensory nociceptors found wrapped around the base of individual hair follicles and respond to hair pull. The discovery of these neurons lays the foundation for exploring their function in chronic pain.


With a combination of in vivo calcium imaging, electrophysiology and optogenetics, this study found that what was previously assumed, that nociceptors make free nerve endings in the skin and don’t innervate specialised structures, is not totally correct. This identifies a new class of cutaneous sensory neurons with an anatomy commonly associated with touch neurons, but with response properties resembling A-delta pain-sensing neurons.

GOT DNA – YOU CAN WORK OUT A PIGMENT PROFILE FOR FREE An international team from Erasmus MC University Medical Center Rotterdam and Indiana University-Purdue University Indianapolis School of Science has developed a novel tool to accurately predict eye, hair and skin colour from human biological material - even a small DNA sample. This all-in-one pigmentation profile tool provides a physical description of the person in a way that has not previously been possible by generating all three pigment traits together. That is amazing, yet even more so, this innovative high-probability and high-accuracy complete pigmentation profile, called HIrisPlex-S System, it is totally free and available on the web. While the site is primarily for Forensic and Anthropological usage, all you need is a piece of DNA, put in the specifications and the webtool will provide a pigmentation profile. The tool is available at Since the site launched in April 2018, there has been an amazing uptake as when I checked (27 August 2018), 104,117,888 phenotypes had been predicted.

The investigators began by turning to calcium imaging with GCaMP6f. This protein, which can be genetically expressed in mice, glows green when it encounters calcium. When a neuron fires an action potential, calcium rushes into the cytosol, where GCaMP6f is waiting. As GCaMP6f binds calcium, the entire cell flashes green, indicating neuronal activation. The study was conducted on mice and remains unclear how mouse hairs and free nerve endings relate to human hairs. It does however advance knowledge of somatosensorial nerve impulses; the sensory process that allows us to feel the outside world, whether a cool breeze, a painful bee sting, or the warmth of a fire. Accordingly, a vast range of potential stimuli must be encoded. Given the sheer number of stimuli, researchers have struggled to identify and categorise all the different types of sensory neurons. Nociceptors, for example, have been categorised by how quickly they conduct their signals, which is determined by the diameter of the fibres and whether they are myelinated or unmyelinated. They’re also categorised according to the neurochemical markers they contain. However, these classifications have been imperfect and do not always accurately reflect their physiology. If this is true of humans, it could go a long way in explaining allodynia, that doesn’t occur in the glabrous (hairless) skin – could it be that chronic unexplained pain can simply be the movement of hair in the skin?

Lakshmi Chaitanya, Krystal Breslin, Sofia Zuñiga, Laura Wirken, Ewelina Pośpiech, Magdalena Kukla-Bartoszek, Titia Sijen, Peter de Knijff, Fan Liu, Wojciech Branicki, Manfred Kayser, Susan Walsh. (2018). The HIrisPlex-S system for eye, hair and skin colour prediction from DNA: Introduction and forensic developmental validation. Forensic Science International: Genetics, 35: 123. DOI: 10.1016/j. fsigen.2018.04.004 APJ

HAIR HAS ITS OWN NERVE SUPPLY (AT LEAST IN MICE) Much research has occurred with and on neurons that transmit the sensation of mechanical pain. Now, researchers add one more piece to the puzzle, by discovering a new APJ 119

Profile for APAN - Aesthetics Practitioners Advisory Network

APJ Vol 38 2018  

Aesthetics Practitioners Journal Volume 38 Spring 2018 - The official publication of the Aesthetics Practitioners Advisory Network (APAN)

APJ Vol 38 2018  

Aesthetics Practitioners Journal Volume 38 Spring 2018 - The official publication of the Aesthetics Practitioners Advisory Network (APAN)