The main bioactive compound in catnip seems to protect cats from mosquitoes. It might protect humans, too.
- For centuries, humans have observed that cats exhibit strange behaviors when exposed to catnip and silver vine.
- A new study examined how the main bioactive compound in these plants affects cats' opioid systems and protects them against mosquito bites.
- The findings suggest that the compound nepetalactol could be used to develop new mosquito repellents for humans.
Nepeta cataria, commonly known as catnip
Johann Georg Sturm (Painter: Jacob Sturm) via WikiPedia/Public Domain<p>In the study, researchers from Iwate University in Japan exposed nepetalactol-laced paper to different types of felids, including domestic and feral cats, a leopard, two jaguars and two lynx. The team also exposed nepetalactol to dogs and mice, but only the cats elicited the expected behavioral response.</p><p>To find out why cats react uniquely to nepetalactol, the researchers measured the animals' endorphin levels before and after they were exposed to the substance. The results showed that nepetalactol raised endorphin levels in cats.</p><p>But when cats were given drugs that blocked opioid receptors, their endorphin levels didn't rise, and their behavior didn't change. This suggests that cats' "μ-opioid system is stimulated by an increase in endogenous β-endorphin secretion when olfactory neurons are activated by these iridoids," the team wrote.</p>
Nepetalactol as a mosquito repellent<p>To test the efficacy of nepetalactol as a mosquito repellant, the researchers anesthetized two groups of cats. For one group, the researchers applied nepetalactol to the cats' heads. The other group was left untreated to serve as a control. The researchers then exposed the cats to Asian tiger mosquitos and counted the number of times the insects bit each group.</p><p>The results showed that the group treated with nepetalactol was much less likely to get bitten, sometimes by as much as 50 percent. The same proved true in a "more natural" experiment, in which cats were allowed to rub their faces on the plants themselves.</p><p style="margin-left: 20px;">"This is convincing evidence that the characteristic rubbing and rolling response functions to transfer plant chemicals that provide mosquito repellency to cats," the team wrote.</p>
The world's deadliest animal<p>While the researchers don't fully understand why nepetalactol activates the μ-opioid system in cats, they think the compound could help humans avoid mosquito bites. After all, some of the study contributors have applied for a patent covering the use of nepetalactol as an insect repellent. Gizmodo <a href="https://gizmodo.com/cats-love-catnip-because-it-protects-them-from-mosquito-1846092518" target="_blank" rel="noopener noreferrer">reports</a> that the researchers even tried applying the compound to their arms, which seemed to prevent mosquito bites.</p><p>For thousands of years, humans have aimed to protect themselves from mosquitos. The Egyptian queen Cleopatra was said to sleep surrounded by a mosquito net. The Romans used vinegar mixtures. And Mississippians turned to the American beautyberry plant. </p><p>Today, DEET is the most widely used mosquito repellent, but it's slightly toxic and can cause side effects, including seizures, though rarely. Developing better mosquito repellents could save many lives. The World Mosquito Program <a href="https://www.worldmosquitoprogram.org/en/learn/mosquito-borne-diseases#:~:text=Nearly%20700%20million%20people%20contract,more%20than%20one%20million%20deaths." target="_blank">reports</a> that mosquito-borne illnesses like malaria and yellow fever affect more than 700 million annually and kill approximately one million. </p>
- Charles Darwin speculated that wingless insects thrived on windy islands so they wouldn't be blown off the land.
- While the reasoning was slightly faulty, researchers have now proved Darwin's 165-year-old "wind hypothesis."
- This finding is yet another example of how environments shape the animals that inhabit them.
Photo: Christian / Adobe Stock<p>Monash researchers looked at three decades of data on various insect species living in Antarctica and 28 Southern Ocean islands—including Svalbard, Jan Mayen, Ellef Ringnes, Bathurst, and St. Matthew—and discovered a trend: wind (as well as low air pressure and freezing temperatures) made flight nearly impossible to resident insects. They simply didn't have the energetic resources needed to take to the sky. Better to crawl around and scavenge.</p><p>Darwin wasn't completely right. He thought the evolutionary adaptations were due purely to wind throwing insects off the island. But nutrition matters too. Flight consumes a ton of energy. The windier it is, the harder insects have to work. Battling a gale requires an inordinate amount of calories. As the team writes, </p><p style="margin-left: 20px;">"Strong winds can also inhibit normal insect flight activity, thereby increasing the energetic costs of flying or maintaining flight structures. This energy trade-off is more complex than Darwin's single-step displacement mechanism because it requires genetic linkage between traits associated with flight ability, flight propensity, and fecundity or survival." </p><p>Still, you have to hand it to the man. During a time when most humans assumed animals were all the result of metaphysical tinkering, Darwin gazed out into nature and connected the dots. His mind has inspired over a century-and-a-half of scientific progress as we continue to build on—and, as this study shows, prove—his theories. </p><p>Darwin knew that every animal is the product of its environment, and therefore must respect both its boons and its boundaries. Talk about a lesson we need today. Environments are known to become very hostile to foreign invaders when pushed too hard. Right now, we're courting disaster. Hopefully, we won't wait for evolution to ground our ambitions. </p><p>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a> and <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a>. His most recent book is</em> "<em><a href="https://www.amazon.com/gp/product/B08KRVMP2M?pf_rd_r=MDJW43337675SZ0X00FH&pf_rd_p=edaba0ee-c2fe-4124-9f5d-b31d6b1bfbee" target="_blank" rel="noopener noreferrer">Hero's Dose: The Case For Psychedelics in Ritual and Therapy</a>."</em></p>
Scientists discover burrows of giant predator worms that lived on the seafloor 20 million years ago.
- Scientists in Taiwan find the lair of giant predator worms that inhabited the seafloor 20 million years ago.
- The worm is possibly related to the modern bobbit worm (Eunice aphroditois).
- The creatures can reach several meters in length and famously ambush their pray.
A three-dimensional model of the feeding behavior of Bobbit worms and the proposed formation of Pennichnus formosae.
Credit: Scientific Reports
Beware the Bobbit Worm!<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="1f9918e77851242c91382369581d3aac"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/_As1pHhyDHY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Scientists regenerate damaged spinal cord nerve fibers with designer protein, helping paralyzed mice walk again.
- Researchers from Germany use a designer protein to treat spinal cord damage in mice.
- The procedure employs gene therapy to regenerate damaged nerve fibers that carry signals to and from the brain.
- The scientists aim to eventually apply the technique to humans.
What is a spinal cord injury?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="88b8d4e44e46b7d5fe49d1f3bca56078"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/dKtBC2Sg_Bg?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span>
Cold hands and feet? Maybe it's your anxiety.
- When we feel anxious, the brain's fight or flight instinct kicks in, and the blood flow is redirected from your extremities towards the torso and vital organs.
- According to the CDC, 7.1% of children between the ages of 3-17 (approximately 4.4 million) have an anxiety diagnosis.
- Anxiety disorders will impact 31% of Americans at some point in their lives.