

Credit: EMBL/Laura Castaldi

The riot of colour before your eyes provides a glimpse at another sense: touch. When something brushes a mouse’s skin, or the temperature around it changes, this bundle of nerves relays that information from touch receptors on the skin to the spinal cord and ultimately the brain, where it can be processed and acted upon. Neurons involved in sensing light touch are shown in green, and two different types of nerve cell involved in sensing pain are labelled red and blue. The image was obtained through a novel technique developed by Paul Heppenstall’s lab at the European Molecular Biology Laboratory (EMBL) in Monterotondo, Italy, which enables researchers to explore tissues in mice in much greater detail than ever before.



Credit: EMBL/Shane Morley

“This is my favorite image – we'd never seen anything like this until we used this technique,” says Heppenstall. “It shows that free nerve endings [red] in the skin split into an incredible number of branches.” Labelled in blue are the nuclei of the skin’s cells.



Credit: EMBL/Laura Castaldi

With this technique, called SNAP-tagging, the EMBL scientists have been able to see the nerves (red) that branch into a ‘basket’ of endings around the base of each hair (thick blue line) with unprecedented detail.



Credit: EMBL/Rahul Dhandapani

The skin’s natural properties create substantial challenges for scientists wanting to study its nerves under the microscope. Labels that relied on large molecules such as the antibody used here, for instance, had difficulty penetrating the skin.



Credit: EMBL/Fernanda de Castro Reis

With the new technique, researchers can use custom-made artificial labels designed to overcome the challenges posed by skin’s natural properties, obtaining much more detailed images of the skin’s nerves.

Additional information

Read more about the technique in the corresponding Press Release

More from Heppenstall on how it was developed

Source Article

Yang, G., Reis, F.C., Sundukova, M., Pimpinella, S., Asaro, A., Castaldi, L., Batti, L., Bilbao, D., Reymond, L., Johnsson, K. & Heppenstall, P.A. Genetic targeting of chemical indicators in vivo. Published online in Nature Methods on 8 December 2014. DOI: 10.1038/nmeth.3207.