Consciousness Cafe - Entheogens and Psychedelic Cultural Transmissions

>DREAM DRUG OR DEMON BREW?
>New Scientist vol 182 issue 2453 - 26 June 2004, page 42
>By Lisa Melton
>http://www.newscientist.com/inprint/index.jsp?id=20040626
>A mind-altering substance used in shamanistic rituals may hold clues to
>dreaming and a natural way of alleviating depression but could also trigger
>schizophrenic hallucinations. Lisa Melton investigates
>IN THE brightly lit chapel, the ceremony is due to begin. Dennis McKenna
>lines up with 500 others to sip the sacrament. It takes 45 minutes before it
>hits him. Then, eyes closed, he finds himself hovering above the Amazon
>basin, aware of the massive forests and the meandering rivers beneath. A
>giant vine winds up towards him and he hurtles down it, shrinking as he goes
>until the leaves themselves seem the size of trees. Shrinking further, he
>finds himself surrounded by a new forest made up of molecules engaged in
>photosynthesis. McKenna, an ethnobotanist from the University of Minnesota
>in Minneapolis, is high on ayahuasca.
>Ayahuasca is not the latest party drug but a foul-tasting plant concoction
>Amazonian people have been downing for centuries. It is the stuff of
>legends, credited with sending people on the most incredible trips. Today
>this bitter tea, also known as hoasca, has become the sacramental ritual of
>two modern religions in Brazil; one of them, the Unio do Vegetal (UDV)
>church, has invited McKenna, an expert on psychoactive plants, and other
>research teams, to scrutinise this sacred brew.
>Their fascination with ayahuasca stems from a little-known mind-altering
>compound called dimethyltryptamine, or DMT, a substance the sacred tea
>contains by the bucketload. When it comes to psychedelic compounds, DMT is
>in a league of its own, as the only hallucinogen our body produces
>naturally.
>Scientists have found DMT pretty much everywhere they've looked in animals,
>plants and fungi. But despite its ubiquity, DMT's role remains a mystery.
>Some believe it fuels vivid dreams, mystical revelations and religious
>exaltation, as well as playing a part in memory. The more sinister
>possibility is that over-producing DMT could tip a person over the edge into
>insanity, inducing the psychotic symptoms of schizophrenia. McKenna and his
>colleagues hope the tripping churchgoers could help them find the answers.
>DMT doesn't hang around long enough for people to study it easily. It acts
>rapidly and is broken down swiftly by the enzyme monoamine oxidase (MAO).
>Normally if you eat or drink it, DMT doesn't stand a chance of getting into
>the brain as MAO in the gut breaks it down.
>Cocktail effect
>Shamans, McKenna discovered, overcame this problem by carefully combining
>plants in the ayahuasca brew. One is the Psychotria viridis bush, which is
>packed with DMT. The other is the vine Banisteriopsis caapi, which contains
>harmine, one of the most effective MAO inhibitors. By inactivating MAO with
>the vine bark, DMT can be absorbed from the gut and crosses the blood-brain
>barrier to trigger a psychedelic response.
>It turns out that harmine-like compounds are also ubiquitous in our bodies.
>This led some researchers to suggest that maybe our bodies regulate the
>levels of DMT in the same way as in the tea, sometimes boosting its activity
>by knocking out MAO so it can fulfil some sort of physiological role.
>Pharmacologist Jordi Riba from the University of Barcelona, Spain, has been
>trying to work out what that physiological role might be, using brain scans
>to study its effect on brain activity. His preliminary results are
>tantalising, showing areas lighting up that are related to memory. Riba
>believes DMT may be involved in retrieving facts and experiences. "When you
>give people ayahuasca, they re-experience memories that are there already.
>It's like pressing a random access button to your stored memories," he says.
>Jace Callaway from the University of Kuopio in Finland has another idea. He
>suggests that endogenous DMT and harmine-like substances may play a role in
>generating dream imagery. "We experience psychedelic states on a regular
>basis while dreaming," he says.
>But while its natural role is still uncertain, a more unnatural role is
>coming to the fore. The effects produced by psychedelic drugs are strikingly
>similar to the symptoms of psychosis. In the 1950s, these similarities led
>to the suggestion that psychoactive compounds like DMT were the cause of
>schizophrenia.
>According to the theory, an enzymatic disturbance in the body could lead to
>overproduction of hallucinogenic compounds. And if MAO activity is low, as
>suspected in people with schizophrenia, the compounds would linger and the
>hallucinations they trigger seep into everyday existence.
>But researchers had always failed to detect consistent differences in DMT
>levels between patients and controls. "I spent my youth collecting and
>analysing gallons of urine from people with schizophrenia," recalls Robin
>Murray from the Institute of Psychiatry in London. "The endogenous DMT
>hypothesis of schizophrenia was never disproved but was just overtaken by
>the dopamine theory, which was more immediately plausible."
>But the theory is enjoying something of a comeback. Alicia Pomilio, an
>organic chemist, and Jorge Ciprian-Ollivier, a psychiatrist, at the
>University of Buenos Aires in Argentina realised that the church
>congregation members could help them to look for the signature of DMT in the
>urine using gas chromatography and mass spectrometry. Once they knew what to
>look for, they were able to detect traces in the urine of patients with
>active schizophrenia but not in controls. It is not clear whether people
>with schizophrenia are producing too much DMT, or too little MAO the result
>would be the same. But the discovery is exciting in that it paves the way to
>finding new drugs to treat schizophrenia.
>But if DMT might be the cause of one medical problem, it could be the cure
>for others. McKenna has found that DMT exerts its effect by attaching mainly
>to one particular type of serotonin uptake site called 5-HT2A, as do other
>psychedelic drugs such as LSD, psilocybin and mescaline. Serotonin is a
>mood-altering neurotransmitter, also known to influence sleep, appetite,
>aggression and love. The newest class of antidepressant drugs, including
>Prozac, are thought to work by blocking the uptake of serotonin into nerve
>cells. Callaway's recent studies suggest that ayahuasca might have some of
>the effects of antidepressant drugs nature's very own Prozac.
>He measured serotonin levels in rats after giving them ayahuasca and says
>the levels of the neurotransmitter "go through the roof". After drinking
>hoasca tea users report a feel-good effect that can last for days. Callaway
>found that hoasca drinkers had a greater than normal density of serotonin
>uptake sites on their blood platelets, where they are easier to measure than
>in the brain. People seem to respond, he says, by creating more receptors.
>When they are not getting a buzz from the tea, the additional receptors
>hunger for more serotonin, pushing the body to produce more.
>But does the brain bump up its number of serotonin uptake sites too? Using a
>brain imaging technique that labels serotonin receptors, Callaway has now
>tested one person, and found signs of a similar upregulation in a
>serotonin-rich region of the brain. Of course, this observation needs
>following up, but it's an encouraging sign. "It's a true tonic effect," says
>Callaway. The sacred tea "apparently does what antidepressants fail to do.
>It could lead to long-term plastic changes in the brain without having to
>pop a pill every day."
>Charles Grob, a psychiatrist at the University of California, Los Angeles,
>School of Medicine, reckons that this sustained effect on mood makes
>ayahuasca a good candidate for treating addictions as well as alleviating
>depression. People with serious alcohol problems and mood disorders were
>transformed by the church. All religions boast life-changing stories, but
>Grob believes the tea itself is important. There is already one centre in
>Peru testing ayahuasca in clinical trials for drug abuse.
>But the researchers are proceeding cautiously. Many people have been taking
>the hallucinogen within the supportive setting of the UDV for 30 years with
>seemingly no adverse side effects. But it is not always so. "If the tea is
>not properly prepared, or in the hands of an individual without the
>appropriate support, the consequences can be negative," says Grob. Even in
>the highly controlled lab setting it can trigger twitching, vomiting and
>diarrhoea. Useful if you are an Amazonian hunter wanting to rid your gut of
>parasites, perhaps, but not exactly convenient if you are wearing your best
>party gear.