A rare genetic mutation, never seen before, protected a man with an inherited form of Alzheimer’s from developing the disease for decades. He is the second person found to have such protection, following a report in 2019 of a woman with a different mutation. Both mutations may have staved off the disease for years by acting in similar ways in the brain, an insight that could lead to new treatments for all forms of Alzheimer’s, researchers report. Both the man and woman were members of a Colombian family who have a mutation in the PSEN1 gene that causes the rare inherited variety of Alzheimer’s. People with “familial” Alzheimer’s usually start showing signs in their 40s. The woman stayed sharp into her 70s, while the man described in the new study was still mentally healthy at 67. “That means they were protected, because they should have gotten the disease 30 years earlier, and they didn’t,” says neurologist Diego Sepulveda-Falla. Amyloid plaques, thought by many researchers to be deeply involved in Alzheimer’s, were abundant in both patients’ brains. But the woman had low levels of another possible culprit, clusters of proteins called tau tangles (orange clumps in this illustration). Surprisingly, the man “was severely affected by tau,” Sepulveda-Falla says. But some key regions had been spared from tau buildup. (🎨: Juan Gaertner/Science Photo Library/Getty Images Plus) #science #alzheimers #neuroscience #disease #dementia #genetic #mutation

Psychedelics go beneath the cell surface to unleash their potentially therapeutic effects. These drugs are showing promise in clinical trials as treatments for mental health disorders. Now, scientists might know why. The substances can get inside nerve cells in the cortex — the brain region important for consciousness — and tell the neurons to grow, researchers report. It was already known that substances like psilocin, which comes from magic mushrooms, and LSD repair neurons by promoting the growth of nerve cell branches that receive information, called dendrites. But how they trigger cell growth was a mystery. The new research shows that access to a protein called the 5-HT2A receptor (highlighted with colors in this microscopic image) inside the cells may be the key to achieve therapeutic effects. (📸: David Olson/UC Davis) #science #neuron #nervecell #brain #neuroscience #psychedelic #lsd #magicmushroom #cortex #cell #microscopic world

Like people, leaves have their limits when it comes to heat. Back in 1864, scientists first reported that the leaves of some plants could survive up to 50° Celsius, only to perish beyond that threshold. When leaves get too hot, their photosynthetic machinery — proteins that convert light energy into sugars — breaks down. More than 150 years later in 2021, a study of 147 tropical plant species reported that the average temperature beyond which photosynthesis failed was 46.7° C. Researchers wanted to figure out how leaves in tropical forests are faring as the globe warms. Using data from a thermal sensor aboard the International Space Station, the scientists captured vegetation temperatures on Earth’s surface in 70-square-meter pixels. That’s about the area that two large tropical trees could fill. The team compared the data with measurements from devices on the planet’s surface to refine their view. The analysis revealed a mosaic of temperatures in forest canopies, including some especially hot leaves. In the upper canopy, roughly 1 in every 10,000 leaves experiences temperatures at least once annually that may be too high for photosynthesis. That might seem a paltry sum, but a photosynthetic breakdown could harm entire forests if climate change is not halted, the scientists warn. (📸: Buena Vista Images/Photodisc/Getty Images Plus) #climate #forests #tropics #trees #globalwarming #science