How Marijuana Works

Rumour has it that marijuana has some pretty interesting effects on the human brain, but how could plant smoke affect our physiology? Well, it's all to do with a case of mistaken identity. Logan Wright goes in search of cells that get duped by dope into having a high old time.

Known variously as marijuana, ganja, cannabis, pot, jays, joints and Mary Jane, the product derived from the cannabis plant is undoubtedly the most popular illicit recreational drug in the world; hence its countless pet names. It can be taken in a variety of creative ways including smoking, eating and drinking, even has incarnations in gum or brownies form.

THC, or tetrahydrocannabinol if you prefer, is a compound within the cannabis plant that, like nicotine or caffeine, may have evolved to ward off herbivores. Its strong psychoactive properties, however, have proven rather seductive to the international drugs scene.

The parts of the brain most affected by marijuana. Click to enlarge.

Once it reaches the bloodstream, THC takes only a few seconds to reach the brain, where it passes itself off as a neurotransmitter - the chemicals which carry messages between neurons in the brain. THC is shaped much like a neurotransmitter called anandamide, which means it can sneak itself into the brain’s anandamide receptor proteins and start to cause mischief. With THC’s spanner in the works, some of the brain’s normal functions really begin to waver.

The receptor proteins are located primarily in three areas of the brain: the hippocampus, responsible for short term memory; the cerebellum, an area controlling coordination; and the basal ganglia, which manages unconscious muscle movement. These are the functions that are altered by THC’s presence, which is why a marijuana user will typically experience impaired coordination, memory lapses, paranoia and altered perception, as well as feeling their heart quicken.

THC's chemical structure. Click to enlarge. Why don't you download the structure, draw a picture and enter it to the THC gallery?

One thing scientists do not thoroughly understand is how THC interacts with dopamine, the chemical that is well known for generating feelings of pleasure and motivation. It’s thought that when THC activates receptor proteins a signal is sent to nearby dopamine terminals in the brain. These then begin to produce inordinate amounts of dopamine, triggering that contented feeling known to so many politicians.

The health effects of marijuana are hotly contested. There is good evidence that it is effective a treating the symptoms of Parkinson’s disease and is used by many people as a treatment for a variety of ills and aches.

However, although it’s generally accepted to be safer than heroine or cocaine, marijuana may have several potential long term effects, which are less helpful. The drug has been linked to an increased incidence of schizophrenia and other mental illnesses. It is also referred to as a “gateway drug” because many marijuana users move from it to more dangerous drugs in search of a more powerful experiencer. For those particularly enamored with the drug’s effects, however, there is consolation: some believe that marijuana use may lead to an eventual perma-high.


Cannabis trivia:

• Archaeologists have reported that marijuana was one of the first plants cultivated by humans. It was being used 10,000 years ago for linen, paper, and garments. In China and India, it was being smoked as early as 2700 BC.
• The Ancient Greek historian Herodotus mentions that Scythian tribes used to pile cannabis leaves on to bonfires during wild festivals.
• George Washington, the first US president, grew cannabis, declaring "Make the most you can of the Indian Hemp seed and sow it everywhere."
• In Vietnam, where cannabis grows wild and free, people rarely smoke it themselves. Instead they feed it to their pigs, who get the serious munchies. The result is that the farmers produce some very fat, and very chilled out, pigs.

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38 dead after being bitten by vampire bats

CARACAS, Venezuela (AP) -- At least 38 Warao Indians have died in remote villages in Venezuela, and medical experts suspect an outbreak of rabies spread by bites from vampire bats.

Warao Indian women grieve over the body of Elbia Rivas, who died from an unidentified illness August 3.

Laboratory investigations have yet to confirm the cause, but the symptoms point to rabies, according to two researchers from the University of California at Berkeley and other medical experts.

The two UC Berkeley researchers -- the husband-and-wife team of anthropologist Charles Briggs and public health specialist Dr. Clara Mantini-Briggs -- said the symptoms include fever, body pains, tingling in the feet followed by progressive paralysis, and an extreme fear of water. Victims tend to have convulsions and grow rigid before death.

Dr. Charles Rupprecht, chief of the rabies program at the Centers for Disease Control and Prevention in Atlanta, agreed with their preliminary diagnosis.

"The history and clinical signs are compatible with rabies," Rupprecht told The Associated Press on Friday. "Prevention is straightforward: Prevent bites and vaccinate those at risk of bites."

Venezuelan health officials are investigating the outbreak and plan to distribute mosquito nets to prevent bat bites and send a medical boat to provide treatment in remote villages on the Orinoco River delta, Indigenous Peoples Minister Nicia Maldonado said Thursday, according to the state-run Bolivarian News Agency.

Outbreaks of rabies spread by vampire bats are a problem in various tropical areas of South America, including Brazil and Peru, Rupprecht said.

He said researchers suspect that in some cases environmental degradation -- including mining, logging or dam construction projects -- may also be contributing to rabies outbreaks.

"Vampire bats are very adaptable," Rupprecht said. And when their roosts are disrupted or their normal prey grow scarce, "Homo sapiens is a pretty easy meal."

More study is needed to confirm through blood or other samples from victims that it is the rabies virus in Venezuela, researchers say.

At least 38 Warao Indians have died since June 2007, and at least 16 have died in the past two months, according to a report the Berkeley researchers and indigenous leaders provided to Venezuelan officials this week.

One village, Mukuboina, lost eight of its roughly 80 inhabitants -- all of them children, Briggs said. All victims throughout the area died within two to seven days from the onset of symptoms, he said.

During a study trip Briggs and Mantini-Briggs made through 30 villages in the river delta, relatives said the victims had been bitten by bats. The couple have worked among the Warao in Delta Amacuro state for years and were invited by indigenous leaders to study the outbreak.

"It's a monster illness," said Tirso Gomez, a Warao traditional healer who said the indigenous group of more than 35,000 people has never experienced anything similar.

Mantini-Briggs, a Venezuelan former health official, said she was surprised to find many Warao villages now have cats -- a new development. "The Waraos told us it was because there were too many bats that were biting the children," she said.

Another tropical medicine expert, Dr. Daniel Bausch of Tulane University in New Orleans, agreed the symptoms and accounts suggest rabies transmitted by bats, and if confirmed, "probably a vaccination campaign would be in order."

The researchers have begun taking precautions. Mantini-Briggs said she started to wonder about her own health Friday while talking with biologist Omar Linares, a bat expert at Simon Bolivar University.

She remembered there was blood on her sheet after sleeping in a hammock in a Warao village two weeks ago. Initially she had dismissed it as an unimportant insect bite or something else, but she remembered her finger hurting that morning and that she saw two small red dots there.

Confirming it must have been a bat bite, Linares suggested she get rabies shots immediately.

"I'm sure a bat bit me," she said. "I remembered and said 'I'm going to get vaccinated.' "

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US Kind of a World Leader in Wind Power Generation

Written by Joshua S Hill

According to the American Wind Energy Association (AWEA), the capacity the US has for generating wind power is expected to increase 45% in 2008. America’s currently installed capacity stands at 19,549MW, up a total of 2,726MW from the end of 2007. Thanks to this number, AWEA is announcing that America is now the US world leader in wind electricity generation.

However this is an announcement based on stats that AWEA is hoping the rest of the world won’t look at too hard.

According to AWEA’s second quarter 2008 market report, they bill the US as the new world leader in the generation of wind power electricity. Looking at Germany’s capacity, for example, sees them with a total of 23,000MW, but never using that full capacity. Apparently the winds in America are stronger, and thus max out the US capacity.

But one important little factoid has been left out of this announcement, allowing the AWEA to make a perfectly legitimate statement, but based in marketing reality.

The US may have a capacity of 19,549MW, expected to grow another 4774MW by the end of this year, but it also has a population of 304.8 million people living on a total area of 9.8 million square kilometers of land. Germany, on the other hand, has only a population of 82 million and a total area of 357,000 square kilometers.

Needless to say, I’m going to say that Germany, and many of the European nations, are doing a lot better in terms of their actual rollout of wind power across their entire country.

And things get worse for the US in light of Congress’s failure to re-extend the production tax credit (PTC). This credit, which once provided a 1.9-cent per kilowatt-hour benefit for the first ten years of a renewable energy facility’s operation, provided not only a benefit but an incentive to install such stations.

According to AWEA executive director Randall Swisher, many projects currently in production are being rushed to completion, so that they can complete prior to the expiration of the PTC at the end of this year. In addition, investments in new projects following the expiration have stalled. “If there is a great deal of uncertainty in the market and in policies in the market, that investment capacity will be deployed elsewhere”, he said. “It’s just ludicrous that the Congress is letting this opportunity slip away.”

So, there you have kind of-good news and bad news for the production of renewable energy in the US; pretty much a sign of the times, really.

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