Rapid molecular evolution of pain insensitivity in multiple African rodents

Noxious substances, called algogens, cause pain and are used as defensive weapons by plants and stinging insects. We identified four previously unknown instances of algogen-insensitivity by screening eight African rodent species related to the naked mole-rat with the painful substances capsaicin, acid (hydrogen chloride, pH 3.5), and allyl isothiocyanate (AITC). Using RNA sequencing, we traced the emergence of sequence variants in transduction channels, like transient receptor potential channel TRPA1 and voltage-gated sodium channel Nav1.7, that accompany algogen insensitivity. In addition, the AITC-insensitive highveld mole-rat exhibited overexpression of the leak channel NALCN (sodium leak channel, nonselective), ablating AITC detection by nociceptors. These molecular changes likely rendered highveld mole-rats immune to the stings of the Natal droptail ant. Our study reveals how evolution can be used as a discovery tool to find molecular mechanisms that shut down pain.
Source: ScienceNOW - Category: Science Authors: Tags: Evolution, Neuroscience r-articles Source Type: news

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April the first is not a joke in my household, instead it heralds the start of this year’s Hysteria Writing Competition. And this year our Writer in Residence is Eithne Cullen. Eithne has been given the challenge of coming up with a blog post each month that challenge you to get your thinking hats on and try something new out. Sometimes ideas come crashing into our heads and sometimes it’s hard to think of things to write about. When I’m stuck I turn to prompts. Each April NaPoRhiMoNet (http://www.napowrimo.net) sends out daily prompts and starters. I tried the first one today. I must admit, I found it ha...
Source: The Hysterectomy Association - Category: OBGYN Authors: Tags: Hysteria Writing hysteria 2020 writer in residence Source Type: news
AbstractThe naked mole-rat (Heterocephalus glaber) is famous for its longevity and unusual physiology. This eusocial species that lives in highly ordered and hierarchical colonies with a single breeding queen, also discovered secrets enabling somewhat pain-free living around 20 million years ago. Unlike most mammals, naked mole-rats do not feel the burn of chili pepper ’s active ingredient, capsaicin, nor the sting of acid. Indeed, by accumulating mutations in genes encoding proteins that are only now being exploited as targets for new pain therapies (the nerve growth factor receptor TrkA and voltage-gated sodium cha...
Source: Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology - Category: Physiology Source Type: research
Over the course of three days, intense pain, redness and swelling of the left fifth toe wrought great havoc to a 67-year-old man [Figure 1]. There was no antecedent trauma, insect bite, nor change in medication. He denied fever, chills or walking barefoot. He had known hypertension and vitamin D deficiency. As a child, he was diagnosed with psoriasis; skin lesions intermittently recurred into adulthood. Both his parents had gout and a grandfather had psoriasis.
Source: The American Journal of Medicine - Category: General Medicine Authors: Tags: DIAGNOSTIC DILEMMA Source Type: research
This reports a case of scorpionism caused by Tityus serrulatus. A male adult was stung while unloading bananas at the supply center in Bel ém, Pará, Brazil. The bananas originated in another state (Bahia) and were brought to Belém by truck. The patient presented with pain, edema, and erythema at the sting site, and was classified as low-risk. The specimen was identified as T. serrulatus and symptomatic treatment and clinical observa tion were advised. The patient was discharged later without further complications. This is the first known envenomation caused by T. serrulatus, a non-native species to Par...
Source: Revista da Sociedade Brasileira de Medicina Tropical - Category: Tropical Medicine Source Type: research
CONCLUSIONS: The clinical presentation of a patient suffering from latrodectism places the clinician in front of a challenging differential diagnosis. Following the suspicion, the first-line doctor is invited to discuss the case with a toxicologist, in order to confirm or exclude the diagnosis and implement all therapeutic measures. In our clinical case, the absence of organic lesions, laboratory tests not suggestive for other causes, and the presence of typical clinical feature suggested the diagnosis of L tredecimguttatus poisoning. This hypothesis was then supported by the close temporal relation between antivenom admin...
Source: Toxicon - Category: Toxicology Authors: Tags: Toxicon Source Type: research
This study aims to identify the rat pain responses induced by experimental V. basalis sting and related-components in the venom. It was observed that unilateral intraplantar injection of crude V. basalis venom could induce several kinds of pain related behaviors in a dose-dependent manner including spontaneous pain, unilateral thermal and unilateral mechanical hypersensitivity at different time courses. Fourteen main fractions were separated from the crude venom of V. basalis using high performance liquid chromatography, among them, five components (1, 3, 4, 9 and 12) could absolutely mimic the crude venom-induced pain beh...
Source: Toxicon - Category: Toxicology Authors: Tags: Toxicon Source Type: research
When I was around 12 years old, I came upon a game being played by a group of boys from the neighborhood. They invited me to play with them, telling me that the game was called butts up. I didn’t know how to play, so they briefly explained the rules. It’s a fairly simple game played with a single ball (like a tennis ball or racketball) thrown against a wall. It didn’t sound too complicated, and I liked games, so I figured I’d give it a try. What they didn’t explain at the time was the penalty for making a mistake three times. Since I was new to the game, I didn’t have any issues with ...
Source: Steve Pavlina's Personal Development Blog - Category: Psychiatry & Psychology Authors: Tags: Emotions Values Source Type: blogs
By being vegan for as long as I have (and vegetarian a few years before that), about 5000 fewer animals were harmed and killed by my lifestyle. But since I blogged about this aspect of my lifestyle (including writing my longest article ever, called How to Be Vegan), I’ve since influenced hundreds (if not thousands) more people to try vegetarianism or veganism for months or years or to adopt such a lifestyle permanently. So the combined impact of going vegan and publicly sharing what I learned is likely beyond 1,000,000 animals by now. That’s based mainly on feedback people have shared with me over the years....
Source: Steve Pavlina's Personal Development Blog - Category: Psychiatry & Psychology Authors: Tags: Health Lifestyle Values Source Type: blogs
ConclusionsThe study presents an exhaustive and updated review on the traditional, pharmacological and phytochemical aspects of H. indicus with notes on its quality control and toxicological information. Although the crude extracts of H. indicus exhibit an array of pharmacological activities, it is high time to identify more active phyto-constituents by bioactivity-guided isolation besides elucidating their structure-activity relationship. More designed investigations are needed to comprehend the multi-target network pharmacology, to clarify the molecular mode of action and to ascertain the efficacious doses of H. indicus....
Source: Journal of Ethnopharmacology - Category: Drugs & Pharmacology Source Type: research
Poisoning by venomous creatures is common. Most is benign, causing only minor irritation or pain, but rarely significant morbidity and mortality can occur. Medically important venomous creatures include snakes, spiders, scorpions and marine creatures. For suspected cases of severe envenoming, seek early expert advice from a clinical toxicologist or poisons information centre. First aid measures include pressure bandaging of the affected limb with immobilization in suspected snakebite and funnel web spider bite, and administration of vinegar after removing tentacles in box jellyfish stings.
Source: Medicine - Category: Internal Medicine Authors: Tags: Poisonous substances Source Type: research
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