Neuroscientists have been trying for nearly a century to get past the built-in guards protecting the brain’s entrance. Researchers at Cornell University believe they have crashed through!
Scientists have thought that once that barrier has been breeched it allows for therapies to be administered that could help in the fight against diseases like Multiple Sclerosis, brain cancer and Alzheimer’s disease.
Blood-brain barriers are centuries that guard the brain from allowing foreign bodies from getting through. The guardians only allow essential nutrients like oxygen, amino acids, glucose, water and essential molecules. They are so good at their job that until now it has been impossible to get past them, and problems have to find another mode of entry.
The key to unlocking the gateway is a molecule known as Adenosine, according to the Cornell researchers. The doorway only opens slightly for a very short time to allow large brain molecules to enter. What they found was that when adenosine receptors are activated in cells that make up the blood brain barrier, allowing medication to be introduced. Although only mice have been used in the study so far, the same adenosine receptors are present in humans.
Even more exciting is that an adenosine-based drug, lexiscan, has been found to briefly open the gates and allow entry. This drug has recently been approved by the FDA, and has been successfully used in heart imaging for very ill patients.
The study was published in the Sept. 14 edition of the Journal of Neuroscience, and funded by the National Institutes of Health. “The biggest hurdle for every neurological disease is that we are unable to treat these diseases because we cannot deliver drugs into the brain,” said associate professor of immunology at Cornell’s College of Veterinary Medicine, Margaret Bynoe. “Big pharmaceutical companies have been trying for 100 years to find out how to traverse the blood-brain barrier and still keep patients alive,” she said. Bynoe, lead author of the study Aaron Carman, and their colleagues have patented the findings and will be involved in drug testing and pre-clinical trials through their newly formed company, Adenios Inc.
According to Bynoe, previously researchers have tried to get across the barrier by modifying drugs so they would bind to the receptors, or letting them ride “piggyback” on other molecules. These have all been met with failure. “Utilizing adenosine receptors seems to be a more generalized gateway across the barrier,” she added. “We are capitalizing on that mechanism to open and close the gateway when we want to.
In this study, researchers successfully were able to transport molecules into the brain, as well as deliver an anti-beta amyloid antibody across the blood-brain barrier. With this they were able see it bind to beta-amyloid plaque that causes Alzheimer’s in mice. “We wanted to see the extent to which we could get large molecules in and whether there was a restriction on size,” Bynoe said.
There are numerous drugs and proteins that are known to block the signals given off by adenosine receptors in mice, so future research on humans will try to identify these drugs. The researchers also want to try to insert brain cancer drugs through the blood-brain barrier, and find out more about the physiology behind the regulating of adenosine receptors that guard the blood-brain barrier.
About the author:
Ron White is a two-time U.S.A. Memory Champion and memory training expert. As a memory keynote speaker he travels the world to speak before large groups or small company seminars, demonstrating his memory skills and teaching others how to improve their memory, and how important a good memory is in all phases of your life. His CDs and memory products are also available online at BrainAthlete.com.
Sources:
Science Daily – Breaching the Blood-Brain Barrier: Finding May Permit Drug Delivery to the Brain for Alzheimer’s, Multiple Sclerosis and Brain Cancers (September 13, 2011) : http://www.sciencedaily.com/releases/2011/09/110913172631.htm
