Researchers have identified a link between the brain and immune system in mice that may explain why psychological stress can exacerbate gut inflammation. The discovery could improve the treatment of chronic gastrointestinal diseases such as inflammatory bowel disease (IBD).

For years, research has shown a link between mental illness and inflammation. This link is particularly evident in IBD or other autoimmune conditions characterized by intestinal inflammation, abdominal pain, and intestinal damage. Even with treatment, people with IBD usually experience an exacerbation of symptoms when stressed.

To understand the mechanism of this association, Christoph Theiss from the University of Pennsylvania and colleagues analyzed mice with symptoms similar to IBD. For one week, the researchers placed eight animals in small test tubes for 3 hours a day to induce stress. They then treated the mice with a chemical irritant for seven days to induce IBD-like symptoms.

Three mice were given a drug to block hormones called glucocorticoids, which the brain signals the body to produce when it feels stressed. The researchers then performed colonoscopies on the mice and scored inflammation and intestinal damage on a scale of 0 to 15, with higher scores indicating worse results. Mice that received the drug had an average of about 5 points, while those that did not have a score of just under 15, indicating that glucocorticoids are important in stress-induced intestinal inflammation.

The researchers then performed a genetic analysis of tissue samples taken from the colons of the animals. They found that mice with persistently elevated levels of glucocorticoids had changes in specialized nerve cells called intestinal glia. Glial cells help maintain neurons and communicate with many different cell types, and they respond to stress hormones by pumping out inflammatory molecules. Enteral glia of mice with elevated levels of glucocorticoids showed increased activity of pro-inflammatory genes.

Genetic analysis has also shown that stress alters neurons in the gut, making them less mature. “The reason this is harmful is because we need mature neurons in the gastrointestinal tract to control intestinal motility,” Theiss says. Together, these findings highlight two branches of the pathway between the brain, gut neurons, and the inflammatory immune response.

The team confirmed these findings in 63 people with IBD by collecting and analyzing tissue samples from the colons of each. Participants also completed a stress-rating questionnaire. People who experienced more stress had more gut damage and a greater increase in inflammatory markers, similar to mice.

Saurab Mehandru The Mount Sinai Health System in New York City says these findings may finally demonstrate the exact brain-gut connection that many have long believed exists in gastrointestinal disorders. “This tells clinicians that you should be looking at the patient as a whole, not just treating the symptoms of flare-ups, but also other problems that may be stress-related,” he says.

“The big question is whether the same pathway can dictate how responsive people are to different treatments,” Theiss says. If so, this could improve the treatment of IBD or lead to new targeted drugs for the condition.

The find of dinosaur bones, which will soon be sent from Niger to the University of Chicago for research, represents the latest victory for paleontology.

Fossils include ancient mammals, flying reptiles, a 40-foot crocodile and “a dozen new large dinosaurs, including huge 60-foot dinosaurs,” says American paleontologist Paul Sereno.

But Chicago won’t be the final resting place for the bones. They should eventually be returned to Niger, which has some of the richest paleontological finds in Africa but no paleontologists of its own.

Nigerian Heritage is a project designed by Dr. Sereno, archaeologist Bube Adamou, and other explorers and government officials. He suggests that museums will not only be able to display fossils, but also conduct their own research for the first time.

“Every time we see that we find new dinosaurs, new fossils that allow us to say that the soil is rich,” says Mr. Adamu, an archaeologist from the Institute for Research in the Humanities, who, as one of Niger’s leading experts on excavations , helped lead a recent expedition. “Niger has an unheard of heritage.”

It is hoped that Niger’s first paleontologists are already taking undergraduate courses.

Goats, cows and pedestrians roam past two unassuming shipping containers down the street of Niger’s coastal capital without a second thought. But inside lies about 50 tons of dinosaur bones wrapped in plaster, potentially some of the most significant paleontological finds ever known in this landlocked West African country, and even on the continent.

There are fossils of approximately 100 different species, some of which are ancient animals that have never been seen before.

“Small animals, mammals, flying reptiles, turtles,” as well as a 40-foot crocodile and “a dozen new large dinosaurs, including huge 60-foot ones,” says American paleontologist Paul Sereno.

It took years to reach the capital, and their journey is not over yet. The first discoveries were made in 2018 and 2019 in the vast expanses of the Sahara desert. Proper excavation, however, would take time and expense, so paleontologists covered them up and buried them, hoping the winds wouldn’t expose them to curious nomads or dangerous smugglers.

Then COVID-19 hit, shutting everything down until finally, last fall, Professor Sereno was able to return to dig up the fossils again.

After a devastating year for Los Angeles mountain lions, researchers have made an encouraging discovery in the hills of southern California: an all-female litter of kittens.

Last week, biologists found three cubs in what the National Park Service called “a dense patch of poison oak nestled among large boulders” between the Santa Monica and Santa Susana mountain ranges. The kittens, which are just over three weeks old and are known as P-113, P-114 and P-115, are healthy, the NPS said in a statement.

“It’s encouraging to see breeding in our small population of mountain lions, especially after all the deaths we’ve documented over the past year,” said Jeff Sikic, lead field biologist in the NPS Mountain Lion Study, which has been studying how animals survive in a fragmented and urbanized environment since 2002. environment.

Since March 2022, 15 mountain lions have died in the study area, Sikic said. Los Angeles Times, most after being hit by vehicles. Among those killed last year was Los Angeles’ darling P-22, once called the Brad Pitt of the mountain lions, who has famously roamed city blocks and under the banner of Hollywood for a decade.

The three kittens were born to P-77, who is estimated by biologists to be between five and six years old and lives between busy freeways 101 and 118. The father likely came from the Santa Susana Mountains and has since returned, NPS said.

“It will be interesting to see how these kittens will use the landscape as they get older and spread out, especially if they decide to stay in the Simi Hills or cross freeways to get into larger natural areas,” Sikic said.

The researchers visited the den while the mother was away and did a short general health assessment of the kittens before returning them. The biologists also tagged each kitten to help identify them in the future.