Malenka and postdoctoral scholar Anatol Kreitzer, PhD, the study's lead author, combined a drug already used to treat Parkinson's disease with an experimental compound that can boost the level of endocannabinoids in the brain. When they used the combination in mice with a condition like Parkinson's, the mice went from being frozen in place to moving around freely in 15 minutes. "They were basically normal," Kreitzer said.

But Kreitzer and Malenka cautioned that their findings don't mean smoking marijuana could be therapeutic for Parkinson's disease.

"It turns out the receptors for cannabinoids are all over the brain, but they are not always activated by the naturally occurring endocannabinoids," said Malenka. The treatment used on the mice involves enhancing the activity of the chemicals where they occur naturally in the brain. "That is a really important difference, and it is why we think our manipulation of the chemicals is really different from smoking marijuana."

The researchers began their study by focusing on a region of the brain known as the striatum. They were interested in that region because it has been implicated in a range of brain disorders, including Parkinson's, depression, obsessive-compulsive disorder and addiction.

The activity of neurons in the striatum relies on the chemical dopamine. A shortage of dopamine in the striatum can lead to Parkinson's disease, in which a person loses the ability to execute smooth motions, progressing to muscle rigidity, tremors and sometimes complete loss of movement. The condition affects 1.5 million Americans, according to the National Parkinson Foundation.

"It turns out that the striatum is much more complicated than imagined," said Malenka. The striatum consists of several different cell types that are virtually indistinguishable under the microscope. To uncover the individual contributions of the cell types, Malenka and Kreitzer used genetically modified mice in which the various cell types were labeled with a fluorescent protein that glows vivid green under a microscope. Having an unequivocal way to identify the cells allowed them to tease apart the functions of the different cell types.

Malenka's lab has long studied how the communication between different neurons is modified by experience and disease. In their examination of two types of mouse striatum cells, Kreitzer and Malenka found that a particular form of adaptation occurs in one cell type but not in the other.

Malenka said this discovery was exciting because no one had determined whether there were functional differences between the various cell types. Their study indicated that the two types of cells formed complementary circuits in the brain.

One of the circuits is thought to be involved in activating motion, while the other is thought to be involved in restraining unwanted movement. "These two circuits are critically involved in a push-pull to select the appropriate movement to perform and to inhibit the other," said Kreitzer.

Dopamine appears to modulate these two circuits in opposite ways. When dopamine is depleted, it is thought that the pathway responsible for inhibiting movement becomes overly activated - leading to the difficulty of initiating motion, the hallmark of Parkinson's disease.

Current treatment for Parkinson's includes drugs that stimulate or mimic dopamine. It turns out that the neurons Kreitzer identified as inhibiting motion had a type of dopamine receptor on them that the other cells didn't. The researchers tested a drug called quinpirole, which mimics dopamine, in mice with a condition similar to human Parkinson's disease, resulting in a small improvement in the mice.

"That was sort of expected," said Malenka. "The cool new finding came when we thought to use drugs that boost the activity of endocannabinoids." Based on prior knowledge of endocannabinoids and dopamine, they speculated that the two chemicals were working in concert to keep the inhibitory pathway in check.

When they added a drug that slows the enzymatic breakdown of endocannabinoids in the brain - URB597, being developed by Kadmus Pharmaceuticals in Irvine, Calif. - the results were striking.

"The dopamine drug alone did a little bit but it wasn't great, and the drug that targeted the enzyme that degrades endocannabinoids basically did nothing alone," Kreitzer said. "But when we gave the two together, the animals really improved dramatically."

This work was supported by a Ruth L. Kirchenstein Fellowship, the National Institutes of Health and the National Parkinson Foundation. Neither researcher has financial ties to Kadmus Pharmaceuticals.

Stanford University Medical Center integrates research, medical education and patient care at its three institutions - Stanford University School of Medicine, Stanford Hospital & Clinics and Lucile Packard Children's Hospital at Stanford. For more information, please visit the Web site of the medical center's Office of Communication & Public Affairs at: http://mednews.stanford.edu

Complete Title: Enhancing Activity of Marijuana-Like Chemicals in Brain Helps Treat Parkinson's Disease

Broadcast Media Contact:
M.A. Malone at 650 723-6912: mamalone@stanford.edu

Contact: Mitzi Baker: mitzibaker@stanford.edu
650-725-2106
Stanford University Medical Center

Source: EurekAlert (DC)
Published: February 7, 2007
Copyright: 2007 American Association for the Advancement of Science
Contact: mitzibaker@stanford.edu
Website: http://www.eurekalert.org/

http://www.treehugger.com/files/2005/04/warmcel_recycle.php

and here

http://www.excelfibre.com/building/products3.html

They could use something like it to make those shipping pallets out of instead of pure wood, seems to me like.

http://greendemolitions.com/

This is all part of the destruction of the rain forests that we were warned about...probably.

There is too much clear cutting in forests of all types. Trees are wasted to make paper, notebook paper, newspapers, toilet paper, paper towels, napkins, paper cups, paper plates, cardboard, and cardboard packaging... when there are more quickly renewable plants to make it with.

Makes me worry about everytime a tree is wasted. What about all those wooden pallets that industry uses...then burns or discards? Trees don't have to be wasted like we tend to do now.

In my son's new house, they used recycled newspapers as insulation in the walls. No, they didn't get tons of newspapers. A company does and grinds them up with liquid and sprays them between the studs. It's supposed to better than fiberglass or foam. It is recycled newspapers which makes me glad that that much more paper wasn't just thrown in a land fill or incinerator.

I think the Earth is tough, too...and I think it goes through weird weather cycles and changes...man or no man.

But if extra brush could cause the Little Ice Age...it makes sense that planting more trees and brush with leaves would be a good idea to inhibit warming. Obviously, it's too late for the parts of the ice caps that have already melted...but it's never too late to try to make it right.

Think of people being able to live in parts of Canada that are too cold now, but might become pleasant.

Finland is losing its winter.

Antarctica might become habitable some day.

***

Wednesday, Feb. 7 (HealthDay News) -- Manipulation of brain molecules similar to those found in marijuana provided dramatic relief of Parkinson's-like symptoms in mice, researchers report.

"This might be a target for treatment that could cure the motor deficits seen in Parkinson's disease," said lead researcher Anatol Kreitzer, whose team published the findings in the Feb. 8 issue of Nature.

Kreitzer emphasized two points, however -- that a lot of work must be done before human trials can begin, and that the study results do not support smoking marijuana as a way to help Parkinson's patients.

The study did involve cannabinoids, molecules that are similar to those found in marijuana. But these cannabinoids occur naturally in the brain, and the study hinged on targeting specific cannabinoids.

"When you smoke a joint, you activate cannabinoid receptors all over the brain," explained Kreitzer, who now is a postdoctoral fellow at Stanford University and will soon move to a research position at the University of California, San Francisco. "That is indiscriminate," Kreitzer said. "In general, you need more specific signaling. Our approach involved only regions of the brain or cells that release dopamine."

Dopamine is crucial, because a lack of that chemical produces the movement problems seen in Parkinson's disease. Kreitzer and Dr. Robert Malenka, professor in psychiatry and behavioral sciences at Stanford, focused on dopamine in the striatum, a region of the brain implicated in Parkinson's disease and a number of other disorders.

"This particular part of the brain doesn't have any obvious anatomy," Kreitzer said. "If you just look at the cells, they all look alike. But it turns out that there are two specific circuits there involved in the control of movement -- a direct pathway that activates motion and an indirect pathway that inhibits motion."

The researchers worked with mice engineered to have a fluorescent protein in one of those circuits. They found that dopamine acts differently in the two circuits. When dopamine is depleted in the pathway that inhibits movement, it becomes overly active.

"The mice that didn't have dopamine in that circuit are completely frozen," Kreitzer said. "They don't walk around at all. To restore plasticity, we tried to activate the dopamine signal."

The mice were given both dopamine and a drug being developed for treatment of anxiety, which acts by slowing the breakdown of brain cannabinoids. "The animals started walking around immediately," Kreitzer said. "There was a five- or sixfold increase in motor activity. If you inhibit the breakdown of these endocannabinoids, you enhance activity even in mice that lack dopamine."

Research now will go in a number of directions, Kreitzer said. "We'd like to understand some other functions of these compounds," he said. Several stages of animal work must be done before human trials can be considered, Kreitzer added.

"A potential role for endocannabinoids for Parkinson disease represents an exciting new area for Parkinson research," said Dr. Michael S. Okun, medical director of the National Parkinson Foundation, which helped fund the research.

Although more study is needed, the work "sheds some light on potentially relevant targets and strategies for treatment of this neurodegenerative disease," said Okun, who is also co-director of the Movement Disorders Center at the University of Florida, Gainesville.

More information:

There's more on Parkinson's disease at the National Parkinson Foundation.

Copyright: 2007 Forbes.com LLC

Someone, please start collecting these little gems.

They follow this pattern. Some wonderful medical properties of pot are (grudgingly) admitted by credible-seeming doctors (i.e., paid establishment toadies), but (say these wizened men of science), "this doesn't mean you should actually take cannabis."

In other words, "Yeah, we found out yet another medical property of marijuana, but we fully endorse locking your law-breaking fanny up with some "Booty Bandits" (see: http://spr.org ) and slaving you (see: UNICOR, etc.). All along we, police, bureaucrats, and big pharma companies, profit from your jailing. Sure, we may (with great fanfare) diddle with patenting expensive synthetic snake-oil chemical analogues of pot's natural ingredients, to sell back to you when you get sick (often) at great profits to us. But we know you'll lap it up, because we can buy media like you breathe air. Enjoy, suckers!"