This Nasal Spray May Clear Your Brain, Not Your Sinuses
WebMD News Archive
Feb. 22, 2001 (Ft. Lauderdale) -- If you've seen the Oscar-nominated film Traffic, you've seen actors mimic the rush that comes from snorting a drug. That "rush," says a Minnesota brain researcher, happens because the drug catches a ride on the nerve highway to the brain, so it reaches pleasure centers in the brain even before it can be detected in the bloodstream.
The researcher says this same nonstop nerve highway can deliver healing drugs directly to the brain, and that simple proposal could someday revolutionize the treatment of stroke or Alzheimer's and Parkinson's diseases.
William H. Frey II, PhD, explains that the nose contains nerve endings connected directly to two very powerful networks: the olfactory nerves, which control the sense of smell, and the trigeminal nerve, which sends sensations from the face and head to the brain.
Those nerves, Frey tells WebMD, provide a "direct shot from the nose to the brain," without stopping first in the bloodstream. That means that a drug can reach the brain in less than 15 minutes, less than half the time it would take if the drug were injected into a vein.
This is important, says Frey, because drugs that enter the bloodstream are often stopped short before making it to the brain by a natural protection mechanism called the "blood-brain barrier." Many drugs for conditions such as stroke or Alzheimer's disease are promising in animal studies but flop when tested in humans because the drugs never make it past the hurdle of this barrier.
He explains that any drug that was previously considered unable to "make it past the blood-brain barrier can be taken back down from the shelf, dusted off, and tried again with this method."
But, according to several other researchers who met recently at the American Stroke Association's 26th International Stroke Conference, Frey's assessment is very optimistic. Frey did demonstrate the effectiveness of his nasal delivery system in a paper delivered at the conference -- but his demonstration was in rats, not people.
He and his colleagues from the Alzheimer's Research Center of the HealthPartners Research Foundation in Saint Paul, Minn., put a few drops of a natural substance called insulin-like growth factor-1 into the noses of rats that had had a stroke.
Earlier experiments demonstrated that this substance can heal injured rat brains, but it had to be applied directly to the brain. In the past, says Frey, "the only way to get it to the human brain would be to drill a hole in the skull and put it in, so it is not considered a practical treatment for humans."
Within hours of getting the drug, the rats showed signed of brain healing: Swelling was reduced, and movement improved, says Frey.