Although immune cells are largely excluded from the central nervous system, they can still closely watch cell debris being removed from the brain to look for infection or injury. Conversely, immune cells also send their own signals that influence brain function.
The microbial communities that live in the gastrointestinal tract of newborns have changed a lot over the past century, which is beneficial Bifidobacterium Species that are far less known, especially in infants who are formula-fed. Understanding why this is so has helped researchers develop probiotics that can restore a more historic microbiome.
More than 40 gray wolves were released to Yellowstone National Park in the mid-1990s, and in the years and decades that followed, researchers attributed the rejuvenation of the ecosystem to the reintroduction of the apex predators. But the nature of the wolves’ influence is still being debated. Efforts are now being made to repeat the experiment and find out how predators affect their surroundings.
Mouse neurons linked to a new memory can be permanently modified by researchers to give them control over their activity. In particular, scientists typically add channelrhodopsin to neurons in a storage network so that they can activate them with blue light. In this way, animals can be asked to remember something, or even to recall an experience that never happened.
In many bird species, the males are lighter in color than the females. In some finches, the gene is BCO2, which encodes a carotenoid-destroying enzyme, appears to explain this sexual dimorphism, which is often expressed in female feathers but not in male feathers.
As the earth’s atmosphere warms, the Arctic ice is melting and sea levels are rising. This pushes salt water further into terrestrial ecosystems, killing forests and threatening farms. The result is a migration of wet tree species to deciduous and pine forests further inland.
Just before the turn of the century, scientists confirmed that adult human brains did indeed create new neurons. Two decades later, the field of neurogenesis research is beginning to understand how these new neurons integrate into existing neural networks to affect learning and memory.