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 - --- MAP posted-by: Jo-D