When something goes wrong in someone's brain -- a tumor, epilepsy, or Alzheimer's, for example -- physicians don't usually have many options. There's surgery, which is invasive and risky, and there's medication, which is usually ineffective: 95% of drugs can't actually reach the brain. What keeps drugs out is known as the blood-brain barrier: a thin, tightly packed layer of cells that surround the brain's blood vessels and act as its gatekeepers. Because the brain requires perfectly balanced microenvironments to function well, this barrier ensures that no toxins, pathogens, or other harmful substances can invade it. Scientists have been trying to breach this barrier for years, and in November 2015, a Canadian research team did it successfully. They injected a patient who had a brain tumor with a chemotherapy drug, then chased it with an injection of microscopic air bubbles. Then, they pulsed low-intensity ultrasound near the brain tumor. It made the bubbles vibrate, gently loosening the cell barrier and allowing the drugs to flow through. This groundbreaking technique could pave the way for noninvasive treatments for all sorts of brain disease. We've collected some awesome videos on this topic. Watch them now to learn more.
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Key Facts In This Video
The brain blocks roughly 95% of medicine taken orally or intravenously. 00:10
The blood-brain barrier is a series of endothelial cells that only let recognized molecules into the brain. Most medicines are rejected by this barrier. 00:45
Some scientists try to trick the gatekeeper cells by combining medicine with recognized molecules or packaging medicines in virus form. 02:07