Our bodies are full of tiny superheroes—antibodies that fight foreign invaders, cells that regenerate, and structures that ensure our systems run smoothly. One such structure is myelin, a material that forms a protective cape around the axons of our nerve cells so that they can send signals quickly and efficiently. But myelin becomes damaged in demyelinating diseases like multiple sclerosis, leaving neurons without their sheaths. Researchers from Caltech now believe they have found a way to help the brain replace damaged myelin.

A key feature of human and animal brains is that they are adaptive; they are able to change their structure and function based on input from the environment and on the potential associations, or consequences, of that input. To learn more about such neural adaptability, researchers at Caltech have explored the brains of insects and identified a mechanism by which the connections in their brain change to form new and specific memories of smells.

Scientists have long seen evidence of social behavior among many species of animals. Dolphins frolic together, lions live in packs, and hornets construct nests that can house a large number of the insects. And, right under our feet, it appears that roundworms are having their own little gatherings in the soil. Until recently, it was unknown how the worms communicate to one another when it's time to come together. Now, however, researchers from Caltech have identified, for the first time, the chemical signals that promote aggregation.

Over the past year, researchers at Caltech, and around the world, have been studying a group of potent antibodies that have the ability to neutralize HIV in the lab; their hope is that they may learn how to create a vaccine that makes antibodies with similar properties. Now, biologists at Caltech led by Nobel Laureate David Baltimore have taken one step closer to that goal: they have developed a way to deliver these antibodies to mice and, in so doing, have effectively protected them from HIV infection.