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It's all about access when it comes to the brain. A strong defense system allows what the brain needs in and keeps out toxins and pathogens. It's an vital function that also stops promising drugs from reaching their target (think: a tumor) and prevents neuroscientists from probing how the brain works. Scientists at Caltech have now engineered viruses that can bypass this barrier in mice and deliver genes to many different types of cells.
Why it matters: In the past few decades, a wealth of tools have been created to study the brain — neurons can be individually labeled and imaged, genes can conceivably be edited, and the brain's cells can be manipulated with light in order to see what effect it has on functions like memory. But that all hinges on getting into the brain.
This new work opens up the brain's intricacies for unprecedented study and possibly treatment of neural disorders (like Parkinson's and Huntington's diseases), brain cancers, and Friedreich's ataxia and other peripheral nervous system diseases.
Read more here.
Humans have stared at the sky for millennia trying to figure out what is out there and what it tells us about our place in the universe. And there — in the gaps between planets and people and particles — hums something that scientists and philosophers have spent a long time trying to understand: space. For as fundamental to our existence and experience as space is, it's hard to describe and define it.
So, we asked four experts a deceptively simple question: What exactly is space?
The majority of life on Earth can't be seen with the naked eye. Bacteria, amoeba, archaea found on hydrothermal vents, single-celled algae, and other unicellular organisms outnumber us multicellular types and have existed on the planet at least 2 billion years longer. Some, like the green algae pediastrum shown above, form colonies from identical cells, each self-sufficient despite their communing.
History lesson: Some of these early occupiers of Earth eventually joined together to share the work of life and cooperate to survive — a key step in life's evolution on Earth (and one that could also inform the search for alien life beyond the planet).
Go deeper: Biologist Sally Warring collects samples of unicellular organisms from New York City's ponds and documents the extraordinary lives of single cells at Pondlife.