Ayahuasca 04: What is it?
From left: a section of ayahuasca vine and chacruna leaves, a pack of “mapacho” cigarettes, and a flask of ayahuasca brew
Over the past few weeks, I’ve shared several posts recounting my first ayahuasca ceremony. While ayahuasca has become quite popular in the U.S. and the rest of the industrialized West, I realize many people don’t actually know what it is or what it does. So today, I want to elucidate some of the mystique surrounding this powerful medicine from the Amazon jungle.
Ayahuasca has been used in South America for at least 1,000 years, as evidenced by the discovery of it (among other psychedelics) in a shaman’s pouch, in what is present day Bolivia.[1]
The history surrounding the use of this psychedelic substance is shrouded in mystery, due to the fact that no written accounts of its use exist prior to Spanish colonization in the 17th century.
But the etymology of this compound word in Quechua hints at its nature:
Aya: “Spirit, soul” or “corpse, dead body”
Waska: “Rope, woody vine, liana”†
The subsequent translations that are most widely used are
“Vine of the soul”
”The rope of death”
In my experience, the latter was more apropos. But that’s a story for an upcoming blog post.
What is Ayahuasca?
Ayahuasca is a psychedelic brew made by boiling plants together, usually over a fire in a large vat, for around 24 hours, until the mixture is a thick, molasses-like brown liquid. Recipes vary, but typically this brew is made from at least two plants: the ayahuasca vine (banisteriopsis caapi), and chacruna (psychotria viridis).
Chacruna is a flowering shrub in the coffee family. The leaves of this plant contain N,N Dimethyltryptamine (DMT)—a potent psychedelic compound. DMT is actually endogenous to human beings and other mammals—meaning our bodies produce this compound in small amounts—and some believe this chemical is released in larger amounts when we dream, and when we die.
The ayahuasca vine can grow up to 30m in length, twisting around itself for structural integrity as it reaches up toward the jungle canopy. Its known “active ingredients” are the beta-carboline alkaloids; harmine, harmaline, and tetrahydroharmine.
When DMT is ingested orally, enzymes in the gut quickly destroy it. This is why these alkaloids are critical: they act as MAOIs, which protect the DMT and allow it to be absorbed into the bloodstream, eventually reaching the brain. While this is the primary mechanism of psychedelic action for ayahuasca tea, it is thought that the compounds of the ayahuasca vine may be psychoactive in their own right. For example, tetrahydroharmine acts as a low grade serotonin reuptake inhibitor (SSRI), a current pharmaceutical intervention against clinical depression, while the MAOI effect from the other alkaloids may increase levels of our own neurotransmitters: serotonin, dopamine, and norepinephrine.
What happens when these plant compounds enter the brain?
DMT is known as a “serotonergic” compound—its structure closely mimics serotonin, a signaling chemical produced by your nerve cells. Serotonin impacts every part of your body, from your emotions to your motor skills—it is considered a natural mood stabilizer, but it is also involved in bodily processes like sleeping, eating, and digesting.[2]
DMT fits like a key into the serotonin receptors of our brains. This brings about several changes. Chief among these, is its effect on the default mode network—the seat of our brain’s executive functioning, the “big boss,” also known as the “ego.” This brain region acts like a dictatorial switchboard operator in the brain, directing different brain areas to communicate and coordinate:
“Evidence suggests that the default mode network (DMN) contributes to the mental exploration of social and emotional content… the desires, beliefs, and intentions of others; in remembering the past; and in planning the future. These functions inherently involve the self as a reference point… and suggest that the DMN may contribute to adaptive behavior by allowing scenarios to be constructed, replayed, and explored in the mind, both to ponder past events and to derive expectations about the future. Failure to reduce DMN activity may result in interference from internal mentation or emotional processing. Overactivity of the DMN may help to explain common symptoms in major depression.”
Presiding over “social and emotional content,” considering “desires, beliefs, and intentions of others," “remembering the past,” and “planning the future,” gives the default mode network a very powerful position:
It controls the stories we believe about who we are.
It controls the tone and nature of our self-talk.
And it controls our outlook for the future.
But what if our Default Mode Network isn’t healthy?
Mine certainly wasn’t, as I learned in the depths of my depression, struggling with toxic self-talk and a dour outlook on the future and life in general. Fortunately, DMT muzzles this dictator in our heads, largely deactivating the default mode network while under the influence of ayahuasca.
And while the leader is temporarily incapacitated, anarchy ensues.
Well, sort of. The brain, now flooded with these serotonin-like compounds, exhibits a global increase in activity and connectivity across brain regions, in a pattern sometimes described as “anarchical." Previously discrete areas of the brain are able to connect more freely, and new neural pathways are formed.
Brain connectivity mapping from another, more well-researched serotonergic substance, psilocybin (magic mushrooms), provides a good representation of what’s going on here:
Credit: Robin Carhart-Harris, Imperial College of London. Watch his Tedx talk here.
In these images, each line represents a communication pathway in the brain.
“Believe it or not, there’s actually an equal number of pathways in each of these two circles, yet they look very different don’t they? Essentially what we’re seeing is the normal brain on the left where communication is confined to particular communities or cliques… for example, visual regions are mostly talking with other visual regions. The psychedelic brain on the right… is much more of an open, freer conversation across the brain.”
–Robin Carhart-Harris, Head of the Centre for Psychedelic Research, Division of Brain Sciences, Imperial College London
Why does this matter? What’s the outcome from these newly formed “brain conversations”?
When unfamiliar areas of the brain are able to connect more freely, new synaptic pathways are formed, which can lead to lasting changes in our thought patterns. Thanks to modern neuroimaging technology, we have a good idea of which areas of the brain exhibit heightened activity under the influence of ayahuasca:
the amygdala
the anterior insula
the left nucleus accumbens
the parahippocampal gyrus
the left subgenual area
Let’s dig a little deeper into just two of these brain regions…
The Amygdala
In 04: Trauma, Part I: What is trauma?, I reported that past emotional trauma leads to “…an enlarged amygdala, and heightened responsivity in this area, which is the central component of the brain’s fear detection and anxiety circuits.”
The amygdala is also a center for memory consolidation and storage, especially for memories that are emotional in nature:
“There's an additional aspect to the amygdala’s involvement in memory. The amygdala doesn't just modify the strength and emotional content of memories; it also plays a key role in forming new memories specifically related to fear… Understanding how the amygdala processes fear is important because of its relevance to post-traumatic stress disorder (PTSD)”
–University of Queensland Brain Institute [3]
Anterior insula
The anterior insula (AI, also known as the anterior insular cortex, AIC) is probably one of the most enigmatic and fascinating brain structures. Nearly every scientific review I found admits the anterior insula is not well-understood, and each study seems to find evidence for a new role in human cognition. These roles are quite varied:
empathy… “supported by numerous neuroimaging studies reporting activation in response to others in pain (e.g. painful physical or thermal heat stimuli) and to [facial] expressions of disgust, fear, anxiety, and happiness.” [4]
compassion
interpersonal concepts, such as fairness and cooperation
social emotions
olfactory perception (our sense of smell)
the emotion of “disgust”—from direct stimuli or by witnessing this reaction in others
decision-making, especially in complex and uncertain environments
orgasm
bowel distension
maternal love
“sudden insight” [5]
interoception (i.e. our perception of sensations from inside our body)
Perhaps explaining the sheer randomness of these disparate functions, was a recent hypothesis from the journal Nature:
“New findings suggest a fundamental role for the AIC in awareness, and thus it needs to be considered as a potential neural correlate of consciousness." [5]
And exhale. If you’ve made it this far, thanks for sticking with me through the neuroscience jargon.
To review, ayahuasca:
…deactivates the default mode network, effectively halting its control over business-as-usual, orderly brain function and its tight regulation of region-to-region communication.
…floods your brain with chemical signaling molecules, opening up dialogue between brain structures that normally don’t get to talk to each other, as well as energizing these areas with increased blood flow and activation.
…One of these regions, the amygdala, is a container of pent up anxiety, emotionally-charged memories, and trauma (and normally kept that way under the watchful eye of the default mode network).
…Another, the anterior insula, is a center of “empathy,” “compassion,” “sudden insight,” and “awareness” at large.
Hypothetically, what would result when painful memories and past emotional wounds, are met with empathy, compassion, and insight?
Healing.
At least that’s what I believe. As countless subjective personal accounts have confirmed, Ayahuasca has a penchant for surfacing repressed memories and trauma (as indeed I experienced in my first ceremony). The activation and enhanced connectivity between the amygdala and anterior insula may very well be the reason for this phenomenon, perhaps constituting one of the core healing powers of ayahuasca.
So, is ayahuasca right for you?
Only you can answer this question. There are several contraindications to Ayahuasca, including potentially fatal drug interactions. Chemical interferences aside, ayahuasca can be a very harsh medicine physically, and even more harrowing psychologically. Most trauma-informed therapies insist on a lighter, gentler approach (and for good reason). What’s more, is the importance of setting—the way ceremonies are run in Peru’s modern ayahuasca tourism industry, make them suboptimal containers for actual trauma-healing work to occur (a fact that became glaringly apparent in my second ayahuasca ceremony, which I’ll detail in next week’s post).
As always, thanks for reading and sharing.
† “Waska” or “huasca”: Quechua is solely a spoken language, and phonetic romanized spellings can vary. The widely accepted written spelling of the word is “Ayahuasca,” which is phonetically identical to “eye-ah-waska”—the fact that no written language exists, is also the reason why ayahuasca’s full history is difficult to trace.
References:
1. National Geographic, Ancient hallucinogens found in 1,000-year-old shamanic pouch
2. Healthline, Serotonin: What You Need to Know
3. The University of Queensland, Where are memories stored in the brain?
4. Journal of Clinical Neurophysiology, Structure and function of the human insula
5. Nature, How do you feel — now? The anterior insula and human awareness
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