Can Scientists Create a Cure for Pain From Scorpions, Spiders, and Centipedes?
Scientists are often portrayed as archetypally rational men, mere calculating machines in human form who propose correct new theories by infallible deduction from what is already known. Science cannot possibly advance in this way, however, and the philosopher Karl Popper pointed out long ago that leaps of the imagination are as necessary to science as they were to art
I have never been able to make such leaps myself, which is why I admire them in others. I remember meeting a researcher into malaria who was trying to produce a vaccine, not against the malarial parasite itself, but against the stomach lining of the mosquitoes that carried the parasite. He hoped that such a vaccine would kill the mosquitoes – causing them to explode in mid-flight, perhaps – and thus prevent the spread of the disease. The idea did not work, but I was impressed by the boldness of the conception.
For the scientist no information is too obscure to be of potential use. And what information could be more obscure than that the desert-dwelling grasshopper mouse that likes eating the bark scorpion, whose sting causes severe pain in all other possible predators and makes them avoid it? Most of us, I think, would say, “All very interesting, professor, but so what?” The scientist, however, asks why the grasshopper mouse is immune to the painful effects of the scorpion venom, and whether, on discovering the reason, it might not help in the development of new analgesics. Mankind has long believed that remedies for its afflictions are to be found in Nature, but only scientists can go about systematically investigating the possibilities. Imagination is a necessary but not sufficient quality for scientific research.
A recent article in the New England Journal of Medicine, in a long-running series that tries to connect basic scientific research with clinical progress, draws attention to research on the grasshopper mouse. The article is provocatively entitled Darwin 1, Pharma 0, thereby drawing our attention to the fact that millions of years of natural selection have done for the grasshopper mouse what a century of research by pharmaceutical companies has not been able to do for Man. The comparison seems neither apt nor fair, but any stick these days is good enough to beat Big Pharma with.
The grasshopper mouse, it seems, has a mutant gene that prevents a component in the scorpion venom from activating the peripheral nerve cells involved in the transmission of pain. Could human pain be alleviated or even abolished if a compound were found that acts on the mechanism that the normal version of the gene, present in all other mammal genomes, controls?
The answer is no, because that mechanism is important only in pain that arises from peripheral nerve disease – a small proportion of all pain. Such pain is often terrible, however, driving people to suicide; but whether it is common enough for drug companies to deem it worthwhile to invest in the research necessary to find and test for a suitable compound remains to be seen.
More hopeful, probably, is research into compounds that block the effect of another, similar gene implicated in a much larger proportion of our pain. The venom of certain centipedes and tarantulas is actually analgesic as well as toxic: the analgesic effect prevents the prey of these beasties from running away (I have noticed that there is a Darwinian explanation for everything). Unfortunately, the analgesic components of centipede and tarantula venom are complex peptides that are unlikely to be reducible to pill form any time soon: so we shall have for the time being to live with at least some of our pain.
The article, however, is a wonderful example of how seemingly obscure observations and research might one day lead to relief of suffering.