THE BRAIN RELEASES A PAINKILLER SIMILAR TO CANNABIS

Alternative To Opiates

This is your brain.

This is your brain on drugs.

This is your brain on a homegrown cousin of marijuana it creates by itself.

That's how a revised anti-drug campaign might go, if it were to take into
account the recent discovery that the brain releases a compound similar to
cannabis to fight pain.

In tests involving rats, researchers at Brown University in Providence, R.I.
found that the brain's pain response system traffics in a naturally produced
cannabinoid known as anandamide, similar to the active agent in marijuana.

The experiment involved an area of the brain known as the periaqueductal
grey (PAG) - part of the brain stem connecting the spinal cord with the
cerebral hemispheres. PAG is nearly identical in animals and humans.

The researchers simulated pain by electrically stimulating the rats' PAG. It
reacted as if it were countering pain by releasing a flood of anandamide,
far above normal levels. When the scientists administered injections of
formalin, a chemical irritant that creates lasting agony, anandamide levels
spiked even higher. (The rats were anaesthetized and unharmed.)

The brain has long been known to produce natural opiates to suppress pain.
The existence of non-opiates, such as anandamide, was discovered two decades
ago, but little has been known about their role.

The Brown researchers were the first to measure anandamide levels, which
they did using a new mass spectrometer technology to determine the
substance's molecular weight. They found the anandamide in a different area
of the PAG than the one that releases natural opiates.

J. Michael Walker, a Brown psychology professor and lead researcher, said
the findings could have ramifications for future drug-based pain treatments,
particularly in instances where opiates do not work.

"There are some types of pain that do not respond well to current
treatments." he said.. "The fact that you have different modulatory systems
that are effective for different types of pain may offer hope."

Walker's team's report appears in the latest issue of the Proceedings of the
National Academy of Science.