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

Psychedelic microdosing in rats shows beneficial effects

March 4, 2019

Science Daily/University of California - Davis

Microdosing -- taking tiny amounts of psychedelic drugs to boost mood and mental acuity -- is based on anecdotal reports of its benefits. Now, a study in rats suggests microdosing can provide relief for symptoms of depression and anxiety, but also has potential negative effects.

The growing popularity of microdosing -- taking tiny amounts of psychedelic drugs to boost mood and mental acuity -- is based on anecdotal reports of its benefits. Now, a study in rats by researchers at the University of California, Davis suggests microdosing can provide relief for symptoms of depression and anxiety, but also found potential negative effects. The work is published March 4 in the journal ACS Chemical Neuroscience.

"Prior to our study, essentially nothing was known about the effects of psychedelic microdosing on animal behaviors," said David Olson, assistant professor in the UC Davis departments of Chemistry and of Biochemistry and Molecular Medicine, who leads the research team. "This is the first time anyone has demonstrated in animals that psychedelic microdosing might actually have some beneficial effects, particularly for depression or anxiety. It's exciting, but the potentially adverse changes in neuronal structure and metabolism that we observe emphasize the need for additional studies."

Testing microdosing claims

Olson's group microdosed male and female rats with DMT, short for N,N-dimethyltryptamine. A psychedelic compound found in ayahuasca tea, DMT's molecular structure is embedded within the structures of popular microdosing drugs such as LSD and psilocybin. The researchers administered one-tenth of the estimated hallucinogenic dose in rats (1 milligram per kilogram of body weight) every third day for two months. Although there is no well-established definition of what constitutes a microdose, people who microdose tend to follow a similar schedule, taking one-tenth of a "trip" dose every three days. The rats were treated for two weeks before beginning behavioral tests relevant to mood, anxiety and cognitive function, and tests were completed during the two-day period between doses.

Olson's group found DMT microdosing helped rats to overcome a "fear response" in a test considered to be a model of anxiety and post-traumatic stress disorder (PTSD) in humans. The researchers also documented reduced immobility in an experiment that measures the effectiveness of antidepressant compounds. Less immobility is associated with antidepressant effects. In tests of cognitive function and sociability, the UC Davis researchers did not find any obvious impairments or improvements, which contrasts with human anecdotal reports.

Microdosing: potential risks

The team documented some potential risks: the dosing regimen significantly increased bodyweight in male rats, for example. It also caused neuronal atrophy in female rats. The latter change was unexpected, as previously Olson's group reported that rats treated with a single high dose of DMT showed increased neuronal growth. The results suggest an acute hallucinogenic dose and chronic, intermittent low doses of DMT produce very different biochemical and structural phenotypes, Olson said.

Despite the potential adverse effects of microdosing, the findings mean that it's possible to decouple the hallucinogenic effects from the therapeutic properties of these compounds.

"Our study demonstrates that psychedelics can produce beneficial behavioral effects without drastically altering perception, which is a critical step towards producing viable medicines inspired by these compounds," Olson said.

https://www.sciencedaily.com/releases/2019/03/190304100015.htm