A new study in Science Signaling combines patient data with mouse experiments to map a pathway connecting elevated glucose to the death of memory-forming neurons. In a cohort of more than 2000 older adults with type 2 diabetes followed for nearly 5 years, higher levels of lactate, a byproduct of how the body processes glucose, were associated with an increased risk of mild cognitive impairment.

To probe causality, the researchers turned to mice, focusing on neurons from the hippocampus, a region central to learning and memory. Under high glucose conditions, these neurons overstabilized a protein called Creb3, which, in turn, ramped up production of an enzyme that generates lactate. The excess piled up, overwhelming the cell’s energy systems and disrupting mitochondria, eventually triggering neuronal death. These changes were then reflected in behavior; in tests like the Morris water maze, which measures spatial learning and memory, diabetic mice performed worse than controls.

Interrupting this pathway with a specially designed peptide reversed the damage. In diabetic mice, the treatment lowered lactate levels, protected hippocampal neurons, and improved performance on memory tests. Because the peptide can cross the blood-brain barrier, it points to a potential strategy for slowing or preventing diabetes-related cognitive decline.

Although human studies are still needed, the findings suggest that what starts as a subtle metabolic buildup may eventually take a toll on the brain—but could potentially be treatable.

For such a common form of weather, it’s perhaps shocking that scientists don’t know what makes some years foggier than others, what pollutants fog carries, or if fog harbors life. And they also don’t know how it might change in a warming world.

For decades, “People would say, well, you know, why does it matter? It’s just a small strip of the world where fog is important,” ecosystem scientist Kathleen Weathers, who dubs herself the “senior stateswoman of fog,” told ScienceAdviser. But fog occurs along the hot western coasts of nations including Peru, South Africa, and Namibia, and is of growing interest for drinking water in Chile’s parched Atacama desert.

Now, the Heising-Simons Foundation has listened, granting $3.65 million to a project studying coastal fog in California. For the first time, researchers will use models and fog collectors from San Diego to Mendocino to systematically measure coastal fog’s chemistry, ecological role, and response to warming. Sunshine-loving Californians won’t be the only benefactors; fog is crucial to the agriculture-heavy Central Valley, which produces more than half of the United States’ lettuce and wine grapes and a quarter of its strawberries.

“People are sort of captivated by the fog, and there’s not a lot of information out there on it,” project co-lead Peter Weiss-Penzias told ScienceAdviser. “I feel extremely fortunate to be able to do this work and to do it at a level that it deserves.”

“There’s a lot of hand-eye coordination involved ,” study co-author Guatum Apte explained. A first observer scans the night sky with a thermal imaging monocular, identifying the heat signature of a bird, and briefly illuminating it with a flashlight. A second observer snaps a photo with a digital camera. Over three autumns, the researchers documented thousands of nocturnally migrating birds, including some surprises. The eastern kingbird, for example, is thought to mainly travel during the day, but the team regularly witnessed members of the species migrating at night. The team also photographed several common backyard birds that are generally considered to be sedentary, year-round residents.

Photographing night-flying birds certainly isn’t for the faint of heart, as it often involves waking up many hours before sunrise and staying out long after sunset. But it’s all worth it to catch a glimpse of a previously invisible bird in flight, said study co-author Cameron Rutt. “It just feels like a magic trick. You’re standing out there in complete darkness, and then voila.”

With contributions from Ana Georgescu, Hannah Richter, and Phie Jacobs

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