“It’s clear that when you give this compound to humans,
it transports them to an alternative reality.” — BRYAN ROTH
Possible clue in
Alzheimer’s roots

By Laura Sanders

A menacing substance builds up in the brains of people with Alzheimer’s disease not because they make too much of it, but rather because they can’t get rid of it, a study appearing online December 9 in Science suggests.

Understanding how the protein, called amyloid-beta, lodges in the brain is likely to yield clues about how Alzheimer’s disease inflicts its devastation.

While there’s no clear consensus on the ultimate cause of Alzheimer’s, many scientists think A-beta is at the core of the disease process. The protein forms deposits considered characteristic of the disease and is thought to interfere with cells in the brain, scrambling its normal operations.

In some rare forms of Alzheimer’s, genetic mutations ramp up A-beta production, flooding the brain with the protein. But the cause of the accumulation is murkier for the most common form of the disease.

The new study suggests that A-beta
clearance is the problem. Researchers
led by Randall Bateman of the Washing-
ton University School of Medicine in St.
Louis designed a way to track the flux of
A-beta in people with Alzheimer’s. The
amino acid leucine was labeled with car-
bon- 13, which is scarce in the body, and
infused into 12 healthy volunteers and 12
volunteers with the disease.

Lab study probes psychoactive drug
Harnessing hallucinogen could bring better pain treatments

By Laura Sanders

Researchers are closer to understanding exactly how a bong packed with Salvia divinorum recently gave “Smiley Miley” the giggles.

Although shamans in Mexico have been chewing the leaves of the hardy mint relative for centuries (and without prompting from a recent You Tube video purporting to show teen idol Miley Cyrus smoking it), little is known about what the increasingly popular recreational drug’s psychoactive substance, salvinorin A, actually does.

A new study provides some data: The hallucinogen kicks off an unusually intense and short-lasting high, with no obvious ill effects, researchers report online December 4 in Drug and Alcohol Dependence.

Matthew W. Johnson, an experimental
psychologist at Johns Hopkins University
School of Medicine in Baltimore, and his
colleagues recruited four volunteers who
had used hallucinogens such as LSD or
psilocybin in the past. Over 20 sessions,
that addictive opiate drugs target.

the participants inhaled various doses of highly purified salvinorin A or a placebo while researchers monitored their vital signs and queried them about their experiences.

The effects of the salvinorin A were remarkably strong, consistent and fast-acting, peaking about two minutes after inhalation, and nearly disappearing in 20 minutes.

As doses increased across sessions, volunteers reported stronger and stronger hallucinations that included car-toonlike images, revisiting childhood memories and contact with an entity.

Studies in animals have shown that salvinorin A acts on molecules in the brain called kappa-opioid receptors. These receptors are part of the pain-dulling opioid system but are not the same receptors memories and contact with an entity. Studies in animals have shown that salvinorin A acts on molecules in the brain called kappa-opioid recep- tors. These receptors are part of the pain-dulling opioid system