Human brain cells wire into a mouse, and cancer's own shield turns fatal

Into that empty space they transplanted human cortical organoids, tiny lab-grown clusters of brain tissue built from stem cells. Within three months the human tissue had grown to make up more than 90 percent of the cortical volume in the mouse's skull 25104. It formed its own blood vessels, wired itself into the mouse's existing nervous system, went electrically active, and sent projections all the way down into the spinal cord 104220. The mice, now called "xenocortical," moved around a small arena while cameras tracked their speed and position on a monitor 250. Pașca is careful about what this is and isn't: "They have a mouse nervous system, mouse sensory organs, and mouse subcortical structures," he told ScienceAlert. "What is unusual is that most of the cortical tissue present in these animals is human-derived" 104.

Working with mouse neurons and publishing in Nature Neuroscience, they discovered axons naturally form small, repeating bulges along their length, more like a string of pearls than a garden hose 7. Crucially, these are not the swellings seen in dying or diseased neurons, which scientists have documented for decades. The Johns Hopkins team found much smaller "non-synaptic varicosities" in axons that were healthy and undamaged, and follow-up work has since found the same pearled shape in human brain tissue, not just mice 7. "Axons are the cables that connect our brain tissue, enabling learning, memory and other functions," Watanabe said. "Understanding the structure of axons is important for understanding brain cell signaling" 7.

Researchers at the University of Vermont, led by Brian Cunniff and Victoria Gibson, went after a strange target: PRX3, an antioxidant enzyme mesothelioma cells rely on to survive the intense oxidative stress their hyperactive metabolism generates inside their own mitochondria. Disable that defense, and the cancer cells effectively poison themselves with their own chemistry 8. In a phase one trial sponsored by RS Oncology, the experimental drug controlled disease progression in 67 percent of patients, shrank tumors in some, and was generally well tolerated; critically ill patients on the drug lived longer than those on standard treatment 8. "It's a disease of a significant unmet medical need," Cunniff said 8.

A team led by Guoyi Yang at the University of Pennsylvania tried to cut through the contradiction using Mendelian randomization, a method that uses naturally occurring genetic variants as a stand-in for a drug's biological effect, isolated from lifestyle or the psychological boost of losing weight 145. Their large-scale genetic study, published in Translational Psychiatry, found that activating the GLP-1 receptor itself is associated with better mental health, a lower risk of depression and bipolar disorder, and hints of a protective effect against substance use disorders 145. "To better understand the psychiatric effects of GLP-1R agonists, we used genetic variants as proxies for GLP-1R activation... to evaluate whether activating this receptor influences mental health outcomes," Yang told PsyPost 145.

Then one afternoon, while her son Lydur sat beside her working a crossword, she sat up, looked him in the face, said "My Lydur, I am going to recite a verse to you," and delivered a childhood hymn in a clear, loud voice. She lay back down, never spoke again, and died within a month 156. This case, documented in a 2011 study by biologist Michael Nahm, is an example of terminal lucidity: a sudden, unexplained return of cognitive function in the days before death in patients with severe dementia or other serious brain damage. Between 60 and 70 percent of dementia caregivers report witnessing it at least once; a study following hospice deaths specifically found it in about 6 percent of cases, which in the US alone works out to roughly 10,000 instances a year 156.

The Italians who founded it had arrived in a wave of over 4.5 million immigrants between 1881 and 1920, crowding into Lower East Side tenements and facing discrimination from Irish Catholics and Protestants alike, who saw their street processions and devotion to a saint's blood relics as "too pagan and idolatrous to be considered 'real' Catholicism," as medievalist and Conversation contributor writes 196. A century later, the same streets fill each September with Sinatra impersonators, Godfather T-shirts, and sausage-and-pepper carts alongside the original religious procession, a mix the writer calls evidence of "a lengthy, strenuous and beautiful process of cultural assimilation" 196.

In 1998, a thousand trucks delivered over 12,000 metric tons of sticky orange waste onto the plot. A lawsuit from a rival juice company shut the project down after just two years, and the site sat forgotten for over a decade 322. When grad student Timothy Treuer went looking for it 16 years later, he couldn't even find the large yellow sign marking the plot, because the vegetation had grown so thick it was swallowed whole. Princeton researchers who studied the site over the following three years found a 176 percent increase in aboveground biomass compared with an identical untreated plot across the road, along with two dozen thriving plant species instead of one, richer soil, a tayra weasel, and a fig tree three feet across that Treuer said "could have had 20 people climbing in that tree at once and it would have supported the weight no problem" 322.

The researchers synthesized human intervention and observational studies across five areas typically flagged as concerns, iron, creatine and carnosine, protein metabolism, fiber fermentation by gut bacteria, and how the body processes plant polyphenols 266. They found the body compensates over time. Long-term plant-based eaters absorb a greater share of non-heme iron, partly because they have lower circulating levels of hepcidin, the hormone that controls how much iron gets absorbed in the first place, and total iron intake among vegans and vegetarians is often as high as, or higher than, omnivores, since legumes, whole grains, and fortified cereals are iron-dense foods 266. Creatine and carnosine, mostly found in animal foods, can be synthesized by the body from amino acid precursors, and well-planned plant-based diets that meet protein targets preserve muscle mass and strength comparably to meat-heavy diets in controlled trials 266.