Ayahuasca compound changes brainwaves to vivid 'waking-dream' state
November 19, 2019
Science Daily/Imperial College London
Scientists have peered inside the brain to show how taking DMT affects human consciousness by significantly altering the brain's electrical activity.
DMT (or dimethyltryptamine) is one of the main psychoactive constituents in ayahuasca, the psychedelic brew traditionally made from vines and leaves of the Amazon rainforest. The drink is typically prepared as part of a shamanic ceremony and associated with unusual and vivid visions or hallucinations.
The latest study is the first to show how the potent psychedelic changes our waking brain waves -- with researchers comparing its powerful effects to 'dreaming while awake'.
The work, led by researchers from the Centre for Psychedelic Research at Imperial College London and published today in the journal Scientific Reports, may help to explain why people taking DMT and ayahuasca experience intense visual imagery and immersive 'waking-dream' like experiences.
DMT is a naturally occurring chemical found in miniscule amounts in the human brain but also in larger amounts in a number of plant species around the world.
Accounts from people who have taken DMT report intense visual hallucinations often accompanied by strong emotional experiences and even 'breakthroughs' into what users describe as an alternate reality or dimension.
But scientists are interested in using the powerful psychoactive compound for research as it produces relatively short but intense psychedelic experiences, providing a window for collecting data on brain activity when consciousness is profoundly altered.
In the latest study, the Imperial team captured EEG measures from healthy participants in a clinical setting, in a placebo-controlled design.
A total of 13 participants were given an intravenous infusion of DMT at the National Institute for Health Research (NIHR) Imperial Clinical Research Facility.
Volunteers were fitted with caps with electrodes to measure the brain's electrical activity, before, during and after their infusion, with the peak of the psychedelic experience lasting around 10 minutes.
Analysis revealed that DMT significantly altered electrical activity in the brain, characterised by a marked drop off in alpha waves -- the human brain's dominant electrical rhythm when we are awake. They also found a short-lived increase in brainwaves typically associated with dreaming, namely, theta waves.
In addition to changes in the types of brainwaves, they also found that, overall, brain activity became more chaotic and less predictable -- the opposite to what is seen in states of reduced consciousness, such as in deep sleep or under general anaesthesia.
"The changes in brain activity that accompany DMT are slightly different from what we see with other psychedelics, such as psilocybin or LSD, where we see mainly only reductions in brainwaves," said lead author Christopher Timmermann, from the Centre for Psychedelic Research.
"Here we saw an emergent rhythm that was present during the most intense part of the experience, suggesting an emerging order amidst the otherwise chaotic patterns of brain activity. From the altered brainwaves and participants' reports, it's clear these people are completely immersed in their experience -- it's like daydreaming only far more vivid and immersive, it's like dreaming but with your eyes open."
Mr Timmermann explains that while it's unclear as to whether DMT may have any clinical potential at this stage, the group hopes to take the work further by delivering a continuous infusion of DMT to extend the window of the psychedelic experience and collect more data.
The team says future studies could include more sophisticated measurements of brain activity, such as fMRI, to show which regions and networks of the brain are affected by DMT. They believe the visual cortex, the large area towards the back of the brain, is likely to be involved.
Dr Robin Carhart-Harris, head of Centre for Psychedelic Research, said: "DMT is a particularly intriguing psychedelic. The visual vividness and depth of immersion produced by high-doses of the substance seems to be on a scale above what is reported with more widely studied psychedelics such as psilocybin or 'magic mushrooms'.
"It's hard to capture and communicate what it is like for people experiencing DMT but likening it to dreaming while awake or a near-death experience is useful.
"Our sense it that research with DMT may yield important insights into the relationship between brain activity and consciousness, and this small study is a first step along that road."
https://www.sciencedaily.com/releases/2019/11/191119075305.htm
'Mystical' psychedelic compound found in normal brains of rats
June 27, 2019
Science Daily/Michigan Medicine - University of Michigan
A study in rats has revealed the presence of naturally occurring dimethyltryptamine, a hallucinogen.
In the past few years, thrill-seekers from Hollywood, Silicon Valley and beyond have been travelling to South America to take part in so-called Ayahuasca retreats. Their goal: to partake in a brewed concoction made from a vine plant Banisteriopsis caapi, traditionally used by indigenous people for sacred religious ceremonies. Drinkers of Ayahuasca experience short-term hallucinogenic episodes many describe as life-changing.
The active ingredient responsible for these psychedelic visions is a molecule called dimethyltryptamine (DMT). For the first time, a team led by Michigan Medicine has discovered the widespread presence of naturally-occurring DMT in the mammalian brain. The finding is the first step toward studying DMT -- and figuring out its role -- within the brains of humans.
"DMT is not just in plants, but also can be detected in mammals," says Jimo Borjigin, Ph.D., of the Department of Molecular and Integrative Physiology. Her interest in DMT came about accidentally. Before studying the psychedelic, her research focused on melatonin production in the pineal gland.
In the seventeenth century, the philosopher Rene Descartes claimed that the pineal gland, a small pinecone-shaped organ located deep in the center of the brain, was the seat of the soul. Since its discovery, the pineal gland, known by some as the third eye, has been shrouded in mystery. Scientists now know it controls the production of melatonin, playing an important role in modulating circadian rhythms, or the body's internal clock. However, an online search for notes to include in a course she was teaching opened Borjigin's eyes to a thriving community still convinced of the pineal gland's mystical power.
The core idea seems to come from a documentary featuring the work of researcher Rick Strassman, Ph.D. with the University of New Mexico School of Medicine. In the mid-1990s, he conducted an experiment in which human subjects were given DMT by IV injection and interviewed after its effects wore off. In a documentary about the experiment, Strassman claims that he believed the pineal gland makes and secretes DMT.
"I said to myself, 'wait, I've worked on the pineal gland for years and have never heard of this,'" she said. She contacted Strassman, requesting the source of his statement. When Strassman admitted that it was just a hypothesis, Borjigin suggested they work together to test it. "I thought if DMT is an endogenous monoamine, it should be very easy to detect using a fluorescence detector."
Using a process in which microdialysis tubing is inserted into a rat brain through the pineal gland, the researchers collected a sample that was analyzed for -- and confirmed -- the presence of DMT. That experiment resulted in a paper published in 2013.
However, Borjigin was not satisfied. Next, she sought to discover how and where DMT was synthesized. Her graduate student, Jon Dean, lead author of the paper, set up an experiment using a process called in situ hybridization, which uses a labeled complementary strand of DNA to localize a specific RNA sequence in a tissue section.
"With this technique, we found brain neurons with the two enzymes required to make DMT," says Borjigin. And they were not just in the pineal gland.
"They are also found in other parts of the brain, including the neocortex and hippocampus that are important for higher-order brain functions including learning and memory."
The results are published in the journal Scientific Reports.
Her team's work has also revealed that the levels of DMT increase in some rats experiencing cardiac arrest. A paper published in 2018 by researchers in the U.K. purported that DMT simulates the near death experience, wherein people report the sensation of transcending their bodies and entering another realm. Borjigin hopes to probe further to discover the function of naturally occurring levels of DMT in the brain -- and what if any role it plays in normal brain functions.
"We don't know what it's doing in the brain. All we're saying is we discovered the neurons that make this chemical in the brain, and they do so at levels similar to other monoamine neurotransmitters."
https://www.sciencedaily.com/releases/2019/06/190627113951.htm