Photo Source: Dewald Kleynhans, University of Pretoria
Scientists discovered ten years ago that nude moles are extremely insensitive to pain. A recent study further explored its response to three stimulants with eight other related species, and identified genes associated with pain insensitivity. This discovery may help to develop more effective analgesics.
Translator: Zhuo Siqi
Revision: Liu Yuechen
Editor: Qi Translated Quotations
African moles are insensitive to many different kinds of pain. Recently, Max, Germany,SciencePublishing research papersThis trait can help them find and adapt to new habitats.Thanks to this genetic variation, plateau moles can
About 10 years ago, the naked mole of MDC became red almost overnight. Gary Lewin from Berlin and Thomas Park from Chicago have discovered the magical sensory world of nude mole mice. Their research shows that nude mole mice have a strong tolerance to pain. They were published in 2008.PLOS BiologyAs mentioned in the paper,Nude moles did not experience pain when exposed to acid or capsaicin.This experiment has attracted worldwide attention.
And published inScienceIn his latest study, Lewin teamed up with colleagues in South Africa and Tanzania to test more examples of pain insensitivity.
In this study, Nigel Bennett, Gary Lewin and Thomas Park of the University of Pretoria in South Africa were selected.Dilute hydrochloric acid, capsaicin and allyl isothiocyanate (AITC, source of pungent taste in mustard)The responses of naked mole mice and other 8 species with close relationship to these substances were observed. These substances usually cause burning sensation in human and other mammalian skin. For example, mustard is a popular seasoning, and AITC is the source of its spicy taste. Researchers believe that moles may be exposed to these substances or their analogues in the wild.
Only plateau moles are not stimulated by mustard
Published in Ole Eigenbrod and Karlien Debus et al.ScienceIn the last paper, I reported thatThree species of mole are insensitive to acid stimulation。 Interestingly, these three moles are not particularly closely related in evolution.Two other moles are insensitive to capsaicin.When the researchers injected capsaicin solution into their paws, they did not have a pain response.
In the experiment,Only one mole was not affected by AITC.But not naked moles, but another burrowing rodent called plateau moles (highveld mole-rat). The mole is named after the plateau in eastern South Africa, where it is a native animal.
Plateau mole. Photo Source: Alison Barker, MDC
The change of ion channel is the key
To study the molecular mechanism of the pain tolerance of the Mole, the researchers extracted some sensory neurons from the spinal cord of nine experimental animals for analysis. There are neurons in the dorsal root ganglion that transmit pain signals to the spinal cord.
Researchers soon discovered that,The activity of two genes changed in individuals who did not feel pain. These two genes and ion channels TRPA1 and Na involved in pain perceptionV1.7.
TRPA1,TRPA1The expression of genes was down-regulated.This is because the plateau mole encodes the NALCN channel (commonly known as the plateau mole).Neurophysiologist Gary Lewin studies the physiological basis of pain
Photo Source: Pablo Castagnola / MDC
Make the mole ache
Lewin was surprised by the results of further experiments.Lewin said. But after a day of administration, the animals no longer react to stimulants.
Daniel Hart, a doctoral student at Nigel Bennett, found that Natal ants were common in the caves of Plateau moles.（Myrmicaria natalensis) activities.
New discoveries in pharmaceutical research
Lewin concluded that:
This discovery may contribute to the development of highly effective analgesics.