Pubdate: Sun, 13 Apr 2014
Source: Tampa Bay Times (FL)
Page: Front page, above the fold
Copyright: 2014 St. Petersburg Times
Contact: http://www.sptimes.com/letters/
Website: http://www.tampabay.com/
Details: http://www.mapinc.org/media/419
Note: Named the St. Petersburg Times from 1884-2011.

WIRED TO WORK WITH MARIJUANA?

STUDIES OF POT'S EFFECTS led to the discovery of cannabinoid receptors
on brain cells. The cannabinoid molecules, produced naturally by the
body, are chemically very similar to THC, the primary chemical
ingredient in marijuana. The receptors are heavily concentrated in
regions of the brain that control bodily functions, and they have
effects familiar to those who use marijuana - medically or
recreationally.

Almost a decade ago, Palmetto resident Ryan Roman started using pot to
cope with the effects of a rare spinal cancer that spread to his
brain. Beating his doctors' predictions, the 31A-year-old is still
alive. He credits marijuana that he inhales through a vaporizer or
ingests in concentrate form.

Roman and other advocates view marijuana as almost a miracle plant,
capable of treating a grabA-bag of maladies like pain, MS, PTSD,
nausea, skin cancer and Lou Gehrig's disease - sweeping claims
reminiscent of old-time patent medicine hucksters.

But in the case of pot, biology does offer theoretical support for
this array of effects.

Years ago, scientists trying to find out why marijuana affects humans
as it does discovered an extensive system of 'cannabinoid receptors,'
little on-off switches that are critical to how some cells function.

These receptors - which pot can activate - are heavily concentrated in
areas of the brain that conA-trol motion, anxiety, memory, judgment,
sensation, vomiting and hunger.

The same mechanisms that make pot smokers crave snacks might help an
AIDS patient regain appeA-tite. Substances that make recreational
imbibers mellow might also reduce pain, anxiety or spasticity.

Scientists disagree about the wisdom of treating illness with pot, but
they rave about the possibility that learning about cannabinoid
receptors might lead to life-saving breakthroughs.

'It is enormously important to our basic knowledge of the brain as
well as our bodies' physiology," said Aron Lichtman, a Virginia
Commonwealth University pharmacology professor. 'It tells us about
marijuana's effects, but more importantly about the possibility of
developing new medication."

Is the brain wired to work with pot?

Puzzle Pieces

More than two decades ago, scientists injected lab rats with a
radioactive version of THC, the primary chemical ingredient in
marijuana. Distinct portions of the rat brains lit up like hotels on
the Las Vegas strip.

The THC had sparked activA-ity by plugging into previously
undiscovered receptors on brain cell membranes. That's a comA-mon way
cell networks operate. One cell sends out molecules that plug - like
puzzle pieces - into receptors on other cells, givA-ing them
instructions.

'It turns out the brain is simA-ply teeming with receptors, conA-sistent
with marijuana having wide-ranging influences on menA-tal function,"
Eckerd College biolA-ogy professor Gregory Gerdeman writes in The Pot
Book: A ComA-plete Guide to Cannabis .

But the body does not produce THC. So scientists reasoned it must
produce something with a very similar chemical structure that would
activate the recepA-tors during normal operations of the body. When
scientists finally isolated these natural signaling molecules, they
labeled them cannabinoids, harkening back to the cannabis plant and
the origiA-nal search for THC's effects.

Cannabinoid receptors show up in the brain, the immune system and a
few organs, often acting to calm down the body's responses before they
get out of control.

Cut your finger and the immune system sends out cells to fight
infection. That causes inflammation, which is harmA-ful if it gets out
of hand. FindA-ing bear spoor on a forest trail should cause anxiety
so you know to get away from danger. But if brain cells panic for
hours, they will damage themselves.

When a cell that contains canA-nabinoid receptors gets excited, it
sends messages to other cells to get something done. Those receiving
cells send back cannaA-binoid molecules that plug into the receptors
to calm the transA-mitting cell down. It's like saying, 'Whoa, That's
enough input, slow down now," Gerdeman writes.

This push-pull communication creates balance, lays down memA-ories and
helps the brain adapt to change, Gerdeman said. Bad things can happen
without it. Mice with blocked cannabinoid receptors cannot function
under stress. Neurons involved in some forms of epilepsy are loaded
with cannabinoid receptors, suggestA-ing that seizures may stem from
impaired cannabinoid signaling.

In Florida, parents of children with severe epilepsy are pushA-ing for
legalization of a non-euA-phoric pot derivative known as Charlotte's
Web. This illustrates the theory behind medical marA-ijuana: When the
body cannot maintain health on its own, pot's ingredients can plug
into canA-nabinoid receptors and make things better.

The Legislature has given Charlotte's Web a sympathetic ear, raising
the prospect that one limited form of medical marijuana will become
legal before voters decide in NovemA-ber whether to legalize pot for
all debilitating medical conditions.

Complexity, Hope

Kevin Sabet, director of the University of Florida's Drug PolA-icy
Institute, agrees that the canA-nabinoid system offers promisA-ing
targets for medical research.

But that 'doesn't justify smokA-ing marijuana any more than the
research around morphine justiA-fies smoking opium or shooting
heroin," Sabet said.

Pot's shotgun approach creates many harmful side effects, he said.
'Herbal marijuana doesn't provide the standardized, reliA-able dosage
we have come to expect from modern medicine." To get there,
scientists are experimenting with cannabiA-noids in pot and the body's
natuA-ral cannabinoid system.

GW Pharmaceuticals, a British company, purifies pot extracts after
cross-breeding strains to accentuate certain chemicals. Sativex, a
nasal spray, is already approved in Europe for treatA-ment of multiple
sclerosis and is well along in the testing process in the United States.

Getting from field to pharA-macy is not easy. Full-blown clinA-ical
trials are hugely expensive and pot presents legal as well as
scientific challenges, including the varied functions of cannabiA-noid
receptors.

After receptors were found on fat cells, a European company won
approval in 2006 to block them with a drug. Sure enough, people lost
weight, even without reducing food intake. U.S drug companies, hoping
for a new obesity drug, launched their own research.

But the drug was yanked from the market after patients with blocked
receptors started getA-ting depressed and even suicidal. That's
consistent with smoked pot's ability to create a temporary sense of
well-being. No receptors, no well-being.

More than a decade ago, studA-ies indicated that THC might inhibit the
progression of some brain cancers, said Sean McAlA-lister, of the
California Pacific Medical Center Research InstiA-tute. But test
subjects dropped out because THC's psychoacA-tive nature - it can
affect mood, behavior and cognition - bothA-ered them so much.

McAllister's group has now found that large amounts of canA-nabidiol -
pot's second most common ingredient - reduce the spread of aggressive
breast canA-cer cells in lab dishes and mice.

Cannabidiol, called CBD for short, is not psychoactive but it also
does not trigger any known cannabinoid receptor, leaving scientists to
wonder how it works and what organs it might affect.

McAllister is eager to raise $500,000 and take the next step
investigating CBD and breast cancer - a small, controlled study in
humans. He is already receiving emails from people eager for a cure
'and that motiA-vates us," he said. 'But with cliniA-cal trials, it's
all guesswork." Ryan Roman thinks that if pot can help sick people
they shouldn't have to wait on drug companies, the Food and Drug
Administration and the rigA-ors of traditional medicine. He has joined
the Florida Cannabis Action Network to lobby the LegA-islature to
legalize all medical marijuana.

'That's the one main reason I'm still here."

Stephen Nohlgren can be reached at  
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